Milky Way - Wikipedia

Milky Way - Wikipedia
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Galaxy containing the Solar System
This article is about the galaxy. For other uses, see
Milky Way (disambiguation)
Milky Way
The
Galactic Center
as seen from
Earth
's night sky (featuring the telescope's
laser guide star
). Listed below is the Galactic Center's information.
Observation data (
J2000
epoch
Constellation
Sagittarius
Right ascension
17
45
40.03599
Declination
−29° 00′ 28.1699″
Distance
7.935–8.277
kpc
(25,881–26,996
ly
Characteristics
Type
Sb; Sbc; SB(rs)bc
Mass
1.15
10
12
Number of stars
100–400 billion (
(1–4)
10
11
12
13
Size
26.8 ± 1.1
kpc
(87,400 ± 3,600
ly
diameter;
25
isophote
10
Half-light radius
(physical)
5.75
0.38
kpc
14
H I scale length
(physical)
70
kpc
(228,000
ly
15
Thickness of
thin disk
220–450 pc (718–1,470 ly)
16
Thickness of
thick disk
2.6 ± 0.5 kpc (8,500 ± 1,600 ly)
16
Angular momentum
10
67
J s
17
Sun's
Galactic rotation period
212 Myr
18
Spiral pattern rotation period
220–360 Myr
19
Bar pattern
rotation period
160–180 Myr
20
Speed relative to
CMB
rest frame
552.2
5.5 km/s
21
Escape velocity at Sun's position
550 km/s
22
Dark matter density at Sun's position
0.0088
+0.0024
−0.0018
pc
−3
0.35
+0.08
−0.07
GeV cm
−3
22
Artist’s impression of the structure of the Milky Way based on data from the
European Space Agency
’s
Gaia
telescope, including the location of the spiral arms, bar, and bulge.
The
Milky Way
or
Milky Way Galaxy
is the
galaxy
that includes the
Solar System
, with the name describing the
galaxy's appearance
from
Earth
: a hazy band of light seen in the
night sky
formed from stars in other arms of the galaxy, which are so far away that they cannot be individually distinguished by the
naked eye
The Milky Way is a
barred spiral galaxy
with a
25
isophotal diameter
estimated at 26.8 ± 1.1
kiloparsecs
(87,400 ± 3,600
light-years
),
10
but only about 1,000 light-years thick at the spiral arms (more at the bar). Recent simulations suggest that a
dark matter
area, also containing some visible stars, may extend up to a diameter of almost 2 million light-years (613 kpc).
28
29
The Milky Way has several
satellite galaxies
and is part of the
Local Group
of galaxies, forming part of the
Virgo Supercluster
which is itself a component of the
Laniakea Supercluster
30
31
It is estimated to contain 100–400 billion stars
32
33
and at least that number of
planets
34
35
The Solar System is located at a radius of about 27,000 light-years (8.3 kpc) from the
Galactic Center
36
on the inner edge of the
Orion Arm
, one of the spiral-shaped concentrations of gas and dust. The stars in the innermost 10,000 light-years form a
bulge
and one or more bars that radiate from the bulge. The Galactic Center is an intense radio source known as
Sagittarius A*
, a
supermassive black hole
of 4.100 (± 0.034) million
solar masses
37
38
The oldest stars in the Milky Way are nearly as old as the
universe
itself and thus probably formed shortly after the
Dark Ages
of the
Big Bang
39
Galileo Galilei
first resolved the band of light into individual stars with his telescope in 1610. Until the early 1920s, most astronomers thought that the Milky Way contained all the stars in the universe.
40
Following the 1920
Great Debate
between the astronomers
Harlow Shapley
and
Heber Doust Curtis
41
observations by
Edwin Hubble
in 1923 showed that the Milky Way was just one of many galaxies.
Mythology
Main article:
Milky Way (mythology)
In the
Babylonian
epic poem
Enūma Eliš
, the Milky Way is created from the severed tail of the primeval salt water
dragon
Tiamat
, set in the sky by
Marduk
, the Babylonian
national god
, after slaying her.
42
43
This story was once thought to have been based on an older
Sumerian
version in which Tiamat is instead slain by
Enlil
of
Nippur
44
45
but is now thought to be purely an invention of Babylonian propagandists with the intention of showing Marduk as superior to the Sumerian deities.
45
Etymology
In
Greek mythology
Zeus
places
Heracles
, his infant son born to
Alcmene
, on
Hera
's breast while she is asleep so the baby will drink
her divine milk
and become immortal. Hera wakes up while breastfeeding and then realizes she is nursing an unknown baby: she pushes the baby away, some of her milk spills, and it produces the band of light known as the Milky Way.
46
In another Greek story, the abandoned Heracles is given by
Athena
to Hera for feeding, but Heracles' forcefulness causes Hera to rip him from her breast in pain.
47
48
49
In Western culture, the name "Milky Way" is derived from its appearance as a dim unresolved "milky" glowing band arching across the night sky. The term is a translation of the
Classical Latin
via lactea
, in turn derived from the
Hellenistic Greek
γαλαξίας
, short for
γαλαξίας κύκλος
galaxías kýklos
), meaning "milky circle". The
Ancient Greek
γαλαξίας
galaxias
) – from root
γαλακτ
-,
γάλα
("milk") +
-ίας
(forming adjectives) – is also the root of "galaxy", the name for our, and later all such, collections of stars.
50
51
52
The Milky Way, or "milk circle", was just one of 11 "circles" the Greeks identified in the sky, others being the
zodiac
, the
meridian
, the
horizon
, the
equator
, the
tropics of Cancer and Capricorn
, the
Arctic Circle
and the
Antarctic Circle
, and two
colure
circles passing through both poles.
53
The English term can be traced back to a story by
Geoffrey Chaucer
c.
1380
See yonder, lo, the Galaxyë
Which men
clepeth
the Milky Wey
For hit is whyt: and somme, parfey,
The House of Fame
54
Other common names
"Birds' Path" is used in several
Uralic
and
Turkic languages
and in the
Baltic languages
. Northern peoples observed that
migratory birds
follow the course of the galaxy
55
while migrating at the Northern Hemisphere. The name "Birds' Path" (in Finnish, Estonian, Latvian, Lithuanian, Bashkir and Kazakh) has some variations in other languages, e.g. "Way of the grey (wild) goose" in Chuvash, Mari and Tatar and "Way of the Crane" in Erzya and Moksha.
The
Kaurna people
of the
Adelaide Plains
of South Australia called the Milky Way
wodliparri
in the
Kaurna language
, meaning "house river".
56
The
Gomeroi people
between
New South Wales
and
Queensland
called the Milky Way
Dhinawan
, the giant "
Emu
in the Sky" that it stretches across the night sky.
57
The Milky Way was traditionally used as a guide by
pilgrims
traveling to the holy site at
Santiago de Compostela
, hence the use of "The Road to Santiago" as a name for the Milky Way.
58
Curiously,
La Voje Ladee
("The Milky Way") was also used to refer to the pilgrimage road.
59
River Ganga of the Sky: this Sanskrit name (
आकाशगंगा
Ākāśagaṃgā
) is used in many Indian languages following a Hindu belief.
The Chinese name "Silver River" (
銀河
) is used throughout East Asia, including Korea and Vietnam (
Ngân hà
). In Japan and Korea, "Silver River" (
Japanese
銀河
romanized
ginga
Korean
은하
RR
eunha
) refers to any galaxy.
The Japanese name for the Milky Way is the "River of Heaven"
天の川
Ama no gawa
, as well as an alternative name in Chinese (
Chinese
天河
pinyin
Tiānhé
). In Vietnamese, "River of Heaven" (
Thiên hà
) refers to any galaxy.
In West Asia, Central Asia and parts of the Balkans the name for the Milky Way is related to the word for
straw
. Today, Persians, Pakistanis, and Turks use it in addition to Arabs. It has been suggested that the term was spread by medieval
Arabs
who in turn borrowed it from Armenians.
60
In
Serbo-Croatian
it is interchangeably called "Kumova slama" (
lit. transl.
Godfather's Straw
) along the "Mliječni put" (
lit. transl.
Milky Way
).
61
In England the Milky Way was called the Walsingham Way in reference to the shrine of
Our Lady of Walsingham
which is in
Norfolk
, England. It was understood to be either a guide to the pilgrims who flocked there, or a representation of the pilgrims themselves.
62
Scandinavian peoples, such as Swedes, have called the galaxy "Winter Street" (
Vintergatan
) as the galaxy is most clearly visible during the winter at the northern hemisphere, especially at high latitudes where the
glow of the Sun late at night
can obscure it during the summer.
Appearance
The Milky Way as seen from a dark site with little
light pollution
The Milky Way is visible as a hazy band of white light, some 30° wide, arching in the
night sky
63
Although all the individual naked-eye stars in the entire sky are part of the Milky Way Galaxy, the term "Milky Way" is limited to this band of light.
64
65
The light originates from the accumulation of
unresolved
stars and other material located in the direction of the
galactic plane
. Brighter regions around the band appear as soft visual patches known as
star clouds
. The most conspicuous of these is the
Large Sagittarius Star Cloud
, a portion of the central
bulge
of the galaxy.
66
Dark regions within the band, such as the
Great Rift
and the
Coalsack
, are areas where
interstellar dust
blocks light from distant stars. Peoples of the southern hemisphere, including the
Inca
and
Australian Aboriginals
, identified these regions as
dark cloud constellations
67
The area of sky that the Milky Way obscures is called the
Zone of Avoidance
68
The Milky Way has a relatively low
surface brightness
. Its visibility can be greatly reduced by background light, such as
light pollution
or moonlight. The sky needs to be darker than about 20.2
magnitude
per square arcsecond in order for the Milky Way to be visible.
69
It should be visible if the
limiting magnitude
is approximately +5.1 or better and shows a great deal of detail at +6.1.
70
This makes the Milky Way difficult to see from brightly lit urban or suburban areas, but very prominent when viewed from
rural areas
when the Moon is below the horizon.
Maps of artificial night sky brightness show that more than one-third of Earth's population cannot see the Milky Way from their homes due to light pollution.
71
As viewed from Earth, the visible region of the Milky Way's
galactic plane
occupies an area of the sky that includes 30
constellations
The
Galactic Center
lies in the direction of
Sagittarius
, where the Milky Way is brightest. From Sagittarius, the hazy band of white light appears to pass around to the
galactic anticenter
in
Auriga
. The band then continues the rest of the way around the sky, back to Sagittarius, dividing the sky into two roughly equal
hemispheres
72
The galactic plane is inclined by about 60° to the
ecliptic
(the path of the Sun in the sky). It is tilted at an angle of 63° to the
celestial equator
73
Astronomical history
See also:
Galaxy § Observation history
Ancient, naked eye observations
In
Meteorologica
Aristotle
(384–322 BC) states that the
Greek philosophers
Anaxagoras
c.
500
–428 BC) and
Democritus
(460–370 BC) proposed that the Milky Way is the glow of stars not directly visible due to Earth's shadow, while other stars receive their light from the Sun, but have their glow obscured by solar rays.
74
Aristotle himself believed that the Milky Way was part of the Earth's upper atmosphere, along with the stars, and that it was a byproduct of stars burning that did not dissipate because of its outermost location in the atmosphere, composing its
great circle
. He said that the milky appearance of the Milky Way
Galaxy
is due to the refraction of the Earth's atmosphere.
75
76
77
The
Neoplatonist
philosopher
Olympiodorus the Younger
c.
495
–570 AD) criticized this view, arguing that if the Milky Way were
sublunary
, it should appear different at different times and places on Earth, and that it should have
parallax
, which it does not. In his view, the Milky Way is celestial. This idea would be influential later in the
Muslim world
78
The
Persian
astronomer
Al-Biruni
(973–1048) proposed that the Milky Way is "a collection of countless fragments of the nature of
nebulous
stars".
79
The
Andalusian
astronomer
Avempace
(died 1138) proposed that the Milky Way was made up of many stars but appeared to be a continuous image in the Earth's atmosphere, citing his observation of a
conjunction
of Jupiter and Mars in 1106 or 1107 as evidence.
76
The Persian astronomer
Nasir al-Din al-Tusi
(1201–1274) in his
Tadhkira
wrote: "The Milky Way, i.e. the Galaxy, is made up of a very large number of small, tightly clustered stars, which, on account of their concentration and smallness, seem to be cloudy patches. Because of this, it was likened to milk in color."
80
Ibn Qayyim al-Jawziyya
(1292–1350) proposed that the Milky Way is "a myriad of tiny stars packed together in the sphere of the fixed stars".
81
Telescopic observations
The shape of the Milky Way as deduced from star counts by
William Herschel
in 1785. The
Solar System
was assumed to be near the center.
Proof of the Milky Way consisting of many stars came in 1610 when
Galileo Galilei
used a
telescope
to study the Milky Way and discovered that it was composed of a huge number of faint stars. Galileo also concluded that the appearance of the Milky Way was due to
refraction
of the Earth's atmosphere.
82
83
75
In a treatise in 1755,
Immanuel Kant
, drawing on earlier work by
Thomas Wright
84
speculated (correctly) that the Milky Way might be a rotating body of a huge number of stars, held together by
gravitational
forces akin to the Solar System but on much larger scales.
85
The resulting disk of stars would be seen as a band in the sky from our perspective inside the disk. Wright and Kant also conjectured that some of the
nebulae
visible in the night sky might be separate "galaxies" themselves, similar to our own. Kant referred to both the Milky Way and the "extragalactic nebulae" as "island universes", a term still current up to the 1930s.
86
87
88
The first attempt to describe the shape of the Milky Way and the position of the Sun within it was carried out by
William Herschel
in 1785 by carefully counting the number of stars in different regions of the visible sky. He produced a diagram of the shape of the Milky Way with the Solar System close to the center.
89
In 1845,
Lord Rosse
constructed a new telescope and was able to distinguish between elliptical and spiral-shaped nebulae. He also managed to make out individual point sources in some of these nebulae, lending credence to Kant's earlier conjecture.
90
91
Photograph of the "Great Andromeda Nebula" from 1899, later identified as the
Andromeda Galaxy
In 1904, studying the
proper motions
of stars,
Jacobus Kapteyn
reported that these were not random, as it was believed in that time; stars could be divided into two streams, moving in nearly opposite directions.
92
It was later realized that Kapteyn's data had been the first evidence of the rotation of the Milky Way,
93
which ultimately led to the finding of galactic rotation by
Bertil Lindblad
and
Jan Oort
In 1917,
Heber Doust Curtis
had observed the nova
S Andromedae
within the
Great Andromeda Nebula
Messier object
31). Searching the photographic record, he found 11 more
novae
. Curtis noticed that these novae were, on average, 10
magnitudes
fainter than those that occurred within the Milky Way. As a result, he was able to come up with a distance estimate of 150,000 parsecs. He became a proponent of the "island universes" hypothesis, which held that the spiral nebulae were independent galaxies.
94
95
In 1920 the
Great Debate
took place between
Harlow Shapley
and Heber Curtis, concerning the nature of the Milky Way, spiral nebulae, and the dimensions of the Universe. To support his claim that the Great Andromeda Nebula is an external galaxy, Curtis noted the appearance of dark lanes resembling the dust clouds in the Milky Way, as well as the significant
Doppler shift
96
The controversy was conclusively settled by
Edwin Hubble
in the early 1920s using the Mount Wilson observatory
2.5 m (100 in) Hooker telescope
. With the
light-gathering power
of this new telescope, he was able to produce
astronomical photographs
that resolved the outer parts of some spiral nebulae as collections of individual stars. He was also able to identify some
Cepheid variables
that he could use as a
benchmark
to estimate the distance to the nebulae. He found that the Andromeda Nebula is 275,000 parsecs from the Sun, far too distant to be part of the Milky Way.
97
98
Satellite observations
Map of stars cataloged by the Gaia release in 2021, displayed as density mesh in the diagram
The
ESA
spacecraft
Gaia
provides distance estimates by determining the
parallax
of a billion stars and is mapping the Milky Way.
99
100
Data from
Gaia
has been described as "transformational". It has been estimated that
Gaia
has expanded the number of observations of stars from about 2 million stars, as of the 1990s, to 2 billion. It has expanded the measurable volume of space by a factor of 100 in radius and a factor of 1,000 in precision.
101
A study in 2020 concluded that
Gaia
detected a wobbling motion of the galaxy, which might be caused by "
torques
from a misalignment of the disc's rotation axis with respect to the principal axis of a non-spherical halo, or from
accreted
matter in the halo acquired during late infall, or from nearby, interacting satellite galaxies and their consequent tides".
102
In April 2024, initial studies and related maps, involving the
magnetic fields
of the Milky Way were reported.
103
Astrography
Sun's location and neighborhood
See also:
Location of Earth
Map of stars cataloged by the
Gaia
release in 2021, overlay on top of artist's conception of the Milky Way overall shape
The
Sun
is near the inner rim of the
Orion Arm
, within the
Local Fluff
of the
Local Bubble
, between the
Radcliffe wave
and
Split
linear structures (formerly
Gould Belt
).
104
Based upon studies of stellar orbits around Sgr A* by Gillessen
et al.
(2016), the Sun lies at an estimated distance of 27.14 ± 0.46 kly (8.32 ± 0.14 kpc)
36
from the Galactic Center. Boehle
et al.
(2016) found a smaller value of 25.64 ± 0.46 kly (7.86 ± 0.14 kpc), also using a star orbit analysis.
105
The Sun is currently 5–30 parsecs (16–98 ly) above, or north of, the central plane of the Galactic disk.
106
The distance between the local arm and the next arm out, the
Perseus Arm
, is about 2,000 parsecs (6,500 ly).
107
The Sun, and thus the Solar System, is located in the Milky Way's
galactic habitable zone
108
109
There are about 208 stars brighter than
absolute magnitude
8.5 within a sphere with a radius of 15 parsecs (49 ly) from the Sun, giving a density of one star per 69 cubic parsecs, or one star per 2,360 cubic light-years (from
List of nearest bright stars
). On the other hand, there are 64 known stars (of any magnitude, not counting 4
brown dwarfs
) within 5 parsecs (16 ly) of the Sun, giving a density of about one star per 8.2 cubic parsecs, or one per 284 cubic light-years (from
List of nearest stars
). This illustrates the fact that there are far more faint stars than bright stars: in the entire sky, there are about 500 stars brighter than
apparent magnitude
4 but 15.5 million stars brighter than apparent magnitude 14.
110
The apex of the Sun's way, or the
solar apex
, is the direction that the Sun travels through the
Local standard of rest
in the Milky Way. The general direction of the Sun's Galactic motion is towards the star
Deneb
near the constellation of
Cygnus
, at an angle of roughly 90 sky degrees to the direction of the Galactic Center. The Sun's orbit about the Milky Way is expected to be roughly elliptical with the addition of perturbations due to the Galactic spiral arms and non-uniform mass distributions. In addition, the Sun passes through the Galactic plane approximately 2.7 times per orbit.
111
This is very similar to how a
simple harmonic oscillator
works with no drag force (damping) term. These oscillations were until recently thought to coincide with
mass lifeform extinction
periods on Earth.
112
A reanalysis of the effects of the Sun's transit through the spiral structure based on CO data has failed to find a correlation.
113
It takes the Solar System about 240 million years to complete one orbit of the Milky Way (a
galactic year
),
114
so the Sun is thought to have completed 18–20 orbits during its lifetime and 1/1250 of a revolution since the
origin of humans
. The
orbital speed
of the Solar System about the center of the Milky Way is approximately 220 km/s (490,000 mph) or 0.073% of the
speed of light
. The Sun moves through the heliosphere at 84,000 km/h (52,000 mph). At this speed, it takes around 1,400 years for the Solar System to travel a distance of 1 light-year, or 8 days to travel 1 AU (
astronomical unit
).
115
The Solar System is headed in the direction of the zodiacal constellation
Scorpius
, which follows the ecliptic.
116
Galactic quadrants
Main article:
Galactic quadrant
A diagram of the Sun's location in the Milky Way; the angles represent longitudes in the
galactic coordinate system
A galactic quadrant, or quadrant of the Milky Way, refers to one of four circular sectors in the division of the Milky Way. In astronomical practice, the delineation of the galactic quadrants is based upon the
galactic coordinate system
, which places the
Sun
as the
origin of the mapping system
117
Quadrants are described using
ordinals
– for example, "1st galactic quadrant",
118
"second galactic quadrant",
119
or "third quadrant of the Milky Way".
120
Viewing from the
north galactic pole
with 0°
(zero degrees)
as the
ray
that runs starting from the Sun and through the Galactic Center, the quadrants are:
Galactic
quadrant
Galactic
longitude
(ℓ)
Reference
1st
0° ≤ ℓ ≤ 90°
121
2nd
90° ≤ ℓ ≤ 180°
119
3rd
180° ≤ ℓ ≤ 270°
120
4th
270° ≤ ℓ ≤ 360°
(360° ≅ 0°)
118
with the galactic longitude
(ℓ)
increasing in the counter-clockwise direction (
positive rotation
) as viewed from
north
of the
Galactic Center
(a view-point several hundred thousand
light-years
distant from Earth in the direction of the constellation
Coma Berenices
); if viewed from south of the Galactic Center (a view-point similarly distant in the constellation
Sculptor
),
would increase in the clockwise direction (
negative rotation
).
General characteristics
Size
A size comparison of the six largest galaxies of the
Local Group
, including the Milky Way
The Milky Way is one of the two largest galaxies in the
Local Group
(the other being the
Andromeda Galaxy
), although the size for its
galactic disc
and how much it defines the isophotal diameter is not well understood.
11
It is estimated that the significant bulk of stars in the galaxy lies within the 26 kiloparsecs (80,000 light-years) diameter, and that the number of stars beyond the outermost disc dramatically reduces to a very low number, with respect to an extrapolation of the exponential disk with the scale length of the inner disc.
122
11
There are several methods being used in astronomy in defining the size of a galaxy, and each of them can yield different results with respect to one another. The most commonly employed method is the
25
standard
– the
isophote
where the photometric brightness of a galaxy in the B-band (445 nm wavelength of light, in the blue part of the
visible spectrum
) reaches 25 mag/arcsec
123
An estimate from 1997 by Goodwin and others compared the distribution of
Cepheid variable
stars in 17 other spiral galaxies to the ones in the Milky Way, and modelling the relationship to their surface brightnesses. This gave an
isophotal diameter
for the Milky Way at 26.8 ± 1.1 kiloparsecs (87,400 ± 3,600 light-years), by assuming that the galactic disc is well represented by an exponential disc and adopting a central surface brightness of the galaxy (μ
) of
22.1
0.3
-mag/arcsec
−2
and a disk scale length (
) of 5.0 ± 0.5 kpc (16,300 ± 1,600 ly).
124
10
125
This is significantly smaller than the Andromeda Galaxy's isophotal diameter, and slightly below the mean isophotal sizes of the galaxies being at 28.3 kpc (92,000 ly).
10
The paper concludes that the Milky Way and Andromeda Galaxy were not overly large spiral galaxies, nor were among the
largest known
(if the former not being the largest) as previously widely believed, but rather average ordinary spiral galaxies.
126
To compare the relative physical scale of the Milky Way, if the
Solar System
out to
Neptune
were the size of a
US quarter
(24.3 mm (0.955 in)), the Milky Way would be approximately at least the greatest north–south line of the
contiguous United States
127
An even older study from 1978 gave a lower diameter for Milky Way of about 23 kpc (75,000 ly).
10
A 2015 paper reported that there is a ring-like filament of stars called Triangulum–Andromeda Ring (TriAnd Ring) rippling above and below the relatively flat
galactic plane
, which alongside
Monoceros Ring
were both suggested to be primarily the result of disk oscillations and wrapping around the Milky Way, at a diameter of at least 50 kpc (160,000 ly),
128
which may be part of the Milky Way's outer disk itself, hence making the stellar disk larger by increasing to this size.
129
A more recent 2018 paper later somewhat ruled out this hypothesis, and supported a conclusion that the Monoceros Ring,
A13
and TriAnd Ring were stellar overdensities rather kicked out from the main stellar disk, with the velocity dispersion of the RR Lyrae stars found to be higher and consistent with halo membership.
130
Another 2018 study revealed the very probable presence of disk stars at 26–31.5 kpc (84,800–103,000 ly) from the Galactic Center or perhaps even farther, significantly beyond approximately 13–20 kpc (40,000–70,000 ly), in which it was once believed to be the abrupt drop-off of the stellar density of the disk, meaning that few or no stars were expected to be above this limit, save for stars that belong to the old population of the galactic halo.
11
131
132
A 2020 study predicted the edge of the Milky Way's
dark matter halo
being around 292 ± 61
kpc
(952,000 ± 199,000
ly
), which translates to a diameter of 584 ± 122
kpc
(1.905 ± 0.3979
Mly
).
28
29
The Milky Way's stellar disk is also estimated to be approximately up to 1.35 kpc (4,000 ly) thick.
133
134
Mass
A schematic profile of the Milky Way.
Abbreviations: GNP/GSP: Galactic North and South Poles
The Milky Way is approximately 0.88 trillion times the mass of the
Sun
in total (8.8
10
11
solar masses), using a cutoff of 200kpc to define the galaxy.
135
Estimates of the mass of the Milky Way vary, depending upon the method and data used. The low end of the estimate range is 5.8
10
11
solar masses
), somewhat less than that of the
Andromeda Galaxy
136
137
138
Measurements using the
Very Long Baseline Array
in 2009 found velocities as large as 254 km/s (570,000 mph) for stars at the outer edge of the Milky Way.
139
Because the orbital velocity depends on the total mass inside the orbital radius, this suggests that the Milky Way is more massive, roughly equaling the mass of Andromeda Galaxy at 7
10
11
within 160,000 ly (49 kpc) of its center.
140
In 2010, a measurement of the radial velocity of halo stars found that the mass enclosed within 80 kilo
parsecs
is 7
10
11
141
In a 2014 study, the mass of the entire Milky Way is estimated to be 8.5
10
11
142
but this is only half the mass of the Andromeda Galaxy.
142
A recent 2019 mass estimate for the Milky Way is 1.29
10
12
143
Much of the mass of the Milky Way seems to be
dark matter
, an unknown and invisible form of matter that interacts gravitationally with ordinary matter. A
dark matter halo
is conjectured to spread out relatively uniformly to a distance beyond one hundred kiloparsecs (kpc) from the Galactic Center. Mathematical models of the Milky Way suggest that the mass of dark matter is 1–1.5
10
12
144
145
146
2013 and 2014 studies indicate a range in mass, as large as 4.5
10
12
147
and as small as 8
10
11
22
By comparison, the total mass of all the stars in the Milky Way is estimated to be between 4.6
10
10
148
and 6.43
10
10
144
In addition to the stars, there is also interstellar gas, comprising 90%
hydrogen
and 10%
helium
by mass,
149
with two thirds of the hydrogen found in the
atomic form
and the remaining one-third as
molecular hydrogen
150
The mass of the Milky Way's interstellar gas is equal to between 10%
150
and 15%
149
of the total mass of its stars.
Interstellar dust
accounts for an additional 1% of the total mass of the gas.
149
In March 2019, astronomers reported that the
virial mass
of the Milky Way Galaxy is
1.54
10
12
solar masses
within a
radius
of about 39.5 kpc (130,000 ly), over twice as much as was determined in earlier studies, suggesting that about 90% of the mass of the galaxy is
dark matter
In September 2023, astronomers reported that the
virial mass
of the Milky Way Galaxy is only
2.06
10
11
solar masses
, only a tenth of the mass of previous studies. The mass was determined from data of the
Gaia
spacecraft
151
Rotation curve
Galaxy rotation curve
for the Milky Way. The vertical axis is the rotation speed about the galactic center. The horizontal axis is the distance from the galactic center. The Sun is marked in yellow. The observed rotation speed curve is marked by data points. The predicted curve based on the stellar mass and gas of the Milky Way is in black. The difference is due to
dark matter
or possibly a modification of gravity like
MOND
. The data shown can be found here.
152
153
154
155
156
157
158
159
160
161
The stars and gas in the Milky Way rotate about its center
differentially
, meaning that the rotation period varies with location. As is typical for spiral galaxies, the orbital speed of most stars in the Milky Way does not depend strongly on their distance from the center. Away from the central bulge or outer rim, the typical stellar orbital speed is between 200 and 220 km/s.
162
Hence the
orbital period
of the typical star is approximately proportional to the length of the path traveled. This is unlike the situation in the Solar System, where two-body gravitational dynamics dominate, and different orbits have significantly different velocities associated with them. The rotation curve (shown in the figure) describes this rotation.
If the Milky Way contained only the mass observed in stars, gas, and other baryonic (ordinary) matter, the rotational speed would decrease with distance from the center. However, the observed curve is relatively flat, indicating that there is additional mass that cannot be detected directly with electromagnetic radiation. This inconsistency is attributed to dark matter.
163
The rotation curve of the Milky Way agrees with the
universal rotation curve
of spiral galaxies, the best evidence for the existence of
dark matter
in galaxies. Alternatively, a minority of astronomers propose that a
modification of the law of gravity
may explain the observed rotation curve.
164
Peculiar velocity
Although
special relativity
states that there is no "preferred"
inertial frame of reference
in space with which to compare the Milky Way, the Milky Way does have a velocity with respect to cosmological
frames of reference
165
One such frame of reference is the
Hubble flow
, the apparent motions of galaxy clusters due to the
expansion of space
. Individual galaxies, including the Milky Way, have
peculiar velocities
relative to the average flow. Thus, to compare the Milky Way to the Hubble flow, one must consider a volume large enough so that the expansion of the Universe dominates over local, random motions. A large enough volume means that the mean motion of galaxies within this volume is equal to the Hubble flow. Astronomers believe the Milky Way is moving at approximately 630 km/s (1,400,000 mph) with respect to this local co-moving frame of reference.
166
167
The Milky Way is moving in the general direction of the
Great Attractor
and other
galaxy clusters
, including the
Shapley Supercluster
, behind it.
168
The Local Group, a cluster of gravitationally bound galaxies containing, among others, the Milky Way and the Andromeda Galaxy, is part of a
supercluster
called the
Local Supercluster
, centered near the
Virgo Cluster
: although they are moving away from each other at 967 km/s (2,160,000 mph) as part of the Hubble flow, this velocity is less than would be expected given the 16.8 million pc distance due to the gravitational attraction between the Local Group and the Virgo Cluster.
169
Another reference frame is provided by the
cosmic microwave background
(CMB), in which the CMB temperature is least distorted by Doppler shift (zero dipole moment). The Milky Way is moving at
552 ± 6 km/s (1,235,000 ± 13,000 mph)
21
with respect to this frame, toward 10.5 right ascension, −24° declination (
J2000
epoch, near the center of
Hydra
). This motion is observed by satellites such as the
Cosmic Background Explorer
(COBE) and the
Wilkinson Microwave Anisotropy Probe
(WMAP) as a dipole contribution to the CMB, as photons in equilibrium in the CMB frame get
blue-shifted
in the direction of the motion and
red-shifted
in the opposite direction.
21
Contents
The
Galactic Center
, as seen by one of the
2MASS
infrared telescopes, is located in the bright upper left portion of the image.
The Milky Way contains between 100 and 400 billion stars
12
13
and at least that many planets.
170
An exact figure would depend on counting the number of very-low-mass stars, which are difficult to detect, especially at distances of more than 300 ly (90 pc) from the Sun. As a comparison, the neighboring Andromeda Galaxy contains an estimated one trillion (10
12
) stars.
171
The Milky Way may contain ten billion
white dwarfs
, a billion
neutron stars
, and a hundred million stellar
black holes
174
175
Filling the space between the stars is a disk of gas and dust called the
interstellar medium
. This disk has at least a comparable extent in radius to the stars,
176
whereas the thickness of the gas layer ranges from hundreds of light-years for the colder gas to thousands of light-years for the warmer gas.
177
178
The disk of stars in the Milky Way does not have a sharp edge beyond which there are no stars. Rather, the concentration of stars decreases with distance from the center of the Milky Way. Beyond a radius of roughly 40,000 light years (13 kpc) from the center, the number of stars per cubic
parsec
drops much faster with radius.
122
Surrounding the galactic disk is a spherical
galactic halo
of stars and
globular clusters
that extends farther outward, but is limited in size by the orbits of two Milky Way satellites, the Large and Small
Magellanic Clouds
, whose
closest approach
to the Galactic Center is about 180,000 ly (55 kpc).
179
At this distance or beyond, the orbits of most halo objects would be disrupted by the Magellanic Clouds. Hence, such objects would probably be ejected from the vicinity of the Milky Way. The integrated
absolute visual magnitude
of the Milky Way is estimated to be around −20.9.
180
181
Both
gravitational microlensing
and planetary transit observations indicate that there may be at least as many planets bound to stars as there are stars in the Milky Way,
34
182
and microlensing measurements indicate that there are more
rogue planets
not bound to host stars than there are stars.
183
184
The Milky Way contains an average of at least one planet per star, resulting in 100–400 billion planets, according to a January 2013 study of the five-planet star system
Kepler-32
by the
Kepler
space observatory.
35
A different January 2013 analysis of Kepler data estimated that at least 17 billion
Earth-sized
exoplanets
reside in the Milky Way.
185
In November 2013, astronomers reported, based on
Kepler space telescope
data, that there could be as many as 40 billion Earth-sized
planets
orbiting in the
habitable zones
of
Sun-like stars
and
red dwarfs
within the Milky Way.
186
187
188
11 billion of these estimated planets may be orbiting Sun-like stars.
189
The nearest exoplanet may be 4.2 light-years away, orbiting the
red dwarf
Proxima Centauri
, according to a 2016 study.
190
Such Earth-sized planets may be more numerous than gas giants,
34
though harder to detect at great distances given their small size. Besides exoplanets, "
exocomets
",
comets
beyond the Solar System, have also been detected and may be common in the Milky Way.
191
More recently, in November 2020, over 300 million habitable exoplanets are estimated to exist in the Milky Way Galaxy.
192
When compared to other more distant galaxies in the universe, the Milky Way galaxy has a below average amount of
neutrino
luminosity making our galaxy a "neutrino desert".
193
Structure
Overview of different elements of the overall structure of the Milky Way
The Milky Way consists of a bar-shaped core region surrounded by a warped disk of
gas, dust
and stars.
194
195
The mass distribution within the Milky Way closely resembles the type Sbc in the
Hubble classification
, which represents spiral galaxies with relatively loosely wound arms.
Astronomers first began to conjecture that the Milky Way is a
barred spiral galaxy
, rather than an ordinary
spiral galaxy
, in the 1960s.
196
197
198
These conjectures were confirmed by the
Spitzer Space Telescope
observations in 2005 that showed the Milky Way's central bar to be larger than previously thought.
199
Galactic Center
Main articles:
Galactic Center
and
Sagittarius A*
Supermassive black hole
Sagittarius A*
imaged by the
Event Horizon Telescope
in radio waves. The central dark spot is the black hole's shadow, which is larger than the
event horizon
Bright
X-ray
flares from
Sagittarius A*
(inset) in the center of the Milky Way, as detected by the
Chandra X-ray Observatory
200
The Sun is 25,000–28,000 ly (7.7–8.6 kpc) from the Galactic Center. This value is estimated using
geometric
-based methods or by measuring selected astronomical objects that serve as
standard candles
, with different techniques yielding various values within this approximate range.
201
105
36
202
203
204
In the inner few kiloparsecs (around 10,000 light-years radius) is a dense concentration of mostly old stars in a roughly spheroidal shape called
the bulge
205
It has been proposed that the Milky Way lacks a
bulge
due to a
collision and merger between previous galaxies
, and that instead it only has a
pseudobulge
formed by its central bar.
206
However, confusion in the literature between the (peanut shell)-shaped structure created by instabilities in the bar, versus a possible bulge with an expected half-light radius of 0.5 kpc, abounds.
207
The Galactic Center is marked by an intense
radio source
named
Sagittarius A*
(pronounced
Sagittarius A-star
). The motion of material around the center indicates that Sagittarius A* harbors a massive, compact object.
208
This concentration of mass is best explained as a
supermassive black hole
201
209
(SMBH) with an estimated mass of 4.1–4.5 million times the
mass of the Sun
209
The rate of accretion of the SMBH is consistent with an
inactive galactic nucleus
, being estimated at
10
−5
per year.
210
Observations indicate that there are SMBHs located near the center of most normal galaxies.
211
212
The nature of the Milky Way's bar is actively debated, with estimates for its half-length and orientation spanning from 1 to 5 kpc (3,000–16,000 ly) and 10–50 degrees relative to the line of sight from Earth to the Galactic Center.
203
204
213
Certain authors advocate that the Milky Way features two distinct bars, one nestled within the other.
214
However,
RR Lyrae-type
stars do not trace a prominent Galactic bar.
204
215
216
The bar may be surrounded by a ring called the "5 kpc ring" that contains a large fraction of the molecular hydrogen present in the Milky Way, as well as most of the Milky Way's
star formation
activity. Viewed from the
Andromeda Galaxy
, it would be the brightest feature of the Milky Way.
217
X-ray emission from the core is aligned with the massive stars surrounding the central bar
210
and the
Galactic ridge
218
In June 2023, astronomers led by
Naoko Kurahashi Neilson
reported using a new cascade neutrino technique
219
to detect, for the first time, the release of
neutrinos
from the
galactic plane
of the Milky Way
galaxy
, creating the first neutrino view of the Milky Way.
220
221
Gamma rays and x-rays
All-sky x-ray image
Since 1970, various gamma-ray detection missions have discovered 511-
keV
gamma rays
coming from the general direction of the Galactic Center. These gamma rays are produced by
positrons
(antielectrons) annihilating with
electrons
. In 2008 it was found that the distribution of the sources of the gamma rays resembles the distribution of low-mass
X-ray binaries
, seeming to indicate that these X-ray binaries are sending positrons (and electrons) into interstellar space where they slow down and annihilate.
222
223
224
The observations were made by both
NASA
and
ESA
's satellites. In 1970 gamma ray detectors found that the emitting region was about 10,000 light-years across with a luminosity of about 10,000 Suns.
223
Illustration of the two gigantic
X-ray
gamma-ray
bubbles (blue-violet) of the Milky Way (center)
In 2010, two gigantic spherical bubbles of high energy gamma-emission were detected to the north and the south of the Milky Way core, using data from the
Fermi Gamma-ray Space Telescope
. The diameter of each of the bubbles is about 25,000 light-years (7.7 kpc) (or about 1/4 of the galaxy's estimated diameter); they stretch up to
Grus
and to
Virgo
on the night-sky of the Southern Hemisphere.
225
226
Subsequently, observations with the
Parkes Telescope
at radio frequencies identified polarized emission that is associated with the Fermi bubbles. These observations are best interpreted as a magnetized outflow driven by star formation in the central 640 ly (200 pc) of the Milky Way.
227
Later, on January 5, 2015,
NASA
reported observing an
X-ray
flare 400 times brighter than usual, a record-breaker, from Sagittarius A*. The unusual event may have been caused by the breaking apart of an
asteroid
falling into the black hole or by the entanglement of
magnetic field lines
within gas flowing into Sagittarius A*.
200
Spiral arms
Further information:
Spiral galaxy
Observed (normal lines) and extrapolated (dotted lines) structure of the spiral arms of the Milky Way, viewed from north of the galaxy – the galaxy rotates clockwise in this view. The gray lines radiating from the Sun's position (upper center) list the three-letter abbreviations of the corresponding constellations
Outside the gravitational influence of the Galactic bar, the structure of the interstellar medium and stars in the disk of the Milky Way is organized into four spiral arms.
228
Spiral arms typically contain a higher density of interstellar gas and dust than the Galactic average as well as a greater concentration of star formation, as traced by
H II regions
229
230
and
molecular clouds
231
The Milky Way's spiral structure is uncertain, and there is currently no consensus on the nature of the Milky Way's arms.
232
Perfect logarithmic spiral patterns only crudely describe features near the Sun,
230
233
because galaxies commonly have arms that branch, merge, twist unexpectedly, and feature a degree of irregularity.
204
233
234
The possible scenario of the Sun within a spur / Local arm
230
emphasizes that point and indicates that such features are probably not unique, and exist elsewhere in the Milky Way.
233
Estimates of the pitch angle of the arms range from about 7° to 25°.
176
235
There are thought to be four spiral arms that all start near the Milky Way Galaxy's center.
236
These are named as follows, with the positions of the arms shown in the image:
Color
Arm(s)
turquoise
Near 3 kpc
and
Perseus Arm
blue
Norma
and
Outer arm
(Along with extension discovered in 2004
237
green
Far 3 kpc
and
Scutum–Centaurus Arm
red
Carina–Sagittarius Arm
There are at least two smaller arms or spurs, including:
orange
Orion–Cygnus Arm
(which contains the Sun and Solar System)
Two spiral arms, the Scutum–Centaurus arm and the Carina–Sagittarius arm, have tangent points inside the Sun's orbit about the center of the Milky Way. If these arms contain an overdensity of stars compared to the average density of stars in the Galactic disk, it would be detectable by counting the stars near the tangent point. Two surveys of near-infrared light, which is sensitive primarily to red giants and not affected by dust extinction, detected the predicted overabundance in the Scutum–Centaurus arm but not in the Carina–Sagittarius arm: the Scutum–Centaurus Arm contains approximately 30% more
red giants
than would be expected in the absence of a spiral arm.
235
238
This observation suggests that the Milky Way possesses only two major stellar arms: the Perseus arm and the Scutum–Centaurus arm. The rest of the arms contain excess gas but not excess old stars.
232
In December 2013, astronomers found that the distribution of young stars and star-forming regions matches the four-arm spiral description of the Milky Way.
239
240
241
Thus, the Milky Way appears to have two spiral arms as traced by old stars and four spiral arms as traced by gas and young stars. The explanation for this apparent discrepancy is unclear.
241
The
Near 3 kpc Arm
(also called the
Expanding 3 kpc Arm
or simply the
3 kpc Arm
) was discovered in the 1950s by astronomer van Woerden and collaborators through
21 centimeter
radio measurements of H
atomic hydrogen
).
242
243
It was found to be expanding away from the central bulge at more than 50
km/s
. It is located in the fourth galactic quadrant at a distance of about 5.2
kpc
from the
Sun
and 3.3 kpc from the
Galactic Center
. The Far 3 kpc Arm was discovered in 2008 by astronomer Tom Dame (
Center for Astrophysics | Harvard & Smithsonian
). It is located in the first galactic quadrant at a distance of 3
kpc
(about 10,000
ly
) from the Galactic Center.
243
244
A simulation published in 2011 suggested that the Milky Way may have obtained its spiral arm structure as a result of repeated collisions with the
Sagittarius Dwarf Elliptical Galaxy
245
It has been suggested that the Milky Way contains two different spiral patterns: an inner one, formed by the Sagittarius arm, that rotates fast and an outer one, formed by the Carina and Perseus arms, whose rotation velocity is slower and whose arms are tightly wound. In this scenario, suggested by numerical simulations of the dynamics of the different spiral arms, the outer pattern would form an outer
pseudoring
246
and the two patterns would be connected by the Cygnus arm.
247
Outside of the major spiral arms is the
Monoceros Ring
(or Outer Ring), a ring of gas and stars torn from other galaxies billions of years ago. However, several members of the scientific community recently restated their position affirming the Monoceros structure is nothing more than an over-density produced by the flared and warped
thick disk
of the Milky Way.
248
The structure of the Milky Way's disk is warped along an
"S" curve
249
Halo
Main article:
Galactic halo
The Galactic disk is surrounded by a
spheroidal halo
of old stars and
globular clusters
, of which 90% lie within 100,000 light-years (30 kpc) of the Galactic Center.
250
However, a few globular clusters have been found farther, such as PAL 4 and AM 1 at more than 200,000 light-years from the Galactic Center. About 40% of the Milky Way's clusters are on
retrograde orbits
, which means they move in the opposite direction from the Milky Way rotation.
251
The globular clusters can follow
rosette orbits
about the Milky Way, in contrast to the
elliptical orbit
of a planet around a star.
252
Although the disk contains dust that obscures the view at some wavelengths, the halo component does not. Active
star formation
takes place in the disk (especially in the spiral arms, which represent areas of high density), but does not take place in the halo, as there is little cool gas to collapse into stars.
114
Open clusters
are also located primarily on the disk.
253
Discoveries in the early 21st century have added dimension to the knowledge of the Milky Way's structure. With the discovery that the disk of the Andromeda Galaxy (M31) extends much farther than previously thought,
254
the possibility of the disk of the Milky Way extending farther is apparent, and this is supported by evidence from the discovery of the Outer Arm extension of the
Cygnus Arm
237
255
and of a similar extension of the
Scutum–Centaurus Arm
256
With the discovery of the
Sagittarius Dwarf Elliptical Galaxy
came the discovery of a ribbon of galactic debris as the polar orbit of the dwarf and its interaction with the Milky Way tears it apart. Upon the 2004 discovery of a ring of galactic debris in an in-plane orbit around the Milky Way, it was initially believed that the debris was the remnant of a system dubbed the
Canis Major Dwarf Galaxy
257
Other scholars believed it to be due to the Galactic warp,
258
a view which has been supported by more recent evidence as of 2021.
259
The
Sloan Digital Sky Survey
of the northern sky shows a huge and diffuse structure (spread out across an area around 5,000 times the size of a full moon) within the Milky Way that does not seem to fit within current models. The collection of stars rises close to perpendicular to the plane of the spiral arms of the Milky Way. The proposed likely interpretation is that a
dwarf galaxy
is merging with the Milky Way. This galaxy is tentatively named the
Virgo Stellar Stream
and is found in the direction of Virgo about 30,000 light-years (9 kpc) away.
260
Gaseous halo
In addition to the stellar halo, the
Chandra X-ray Observatory
XMM-Newton
, and
Suzaku
have provided evidence that there is also a gaseous halo containing a large amount of hot gas. This halo extends for hundreds of thousands of light-years, much farther than the stellar halo and close to the distance of the Large and Small
Magellanic Clouds
. The mass of this hot halo is nearly equivalent to the mass of the Milky Way itself.
261
262
263
The temperature of this halo gas is between 1 and 2.5 million K (1.8 and 4.5 million °F).
264
Observations of distant galaxies indicate that the Universe had about one-sixth as much
baryonic
(ordinary) matter as dark matter when it was just a few billion years old. However, only about half of those baryons are accounted for in the modern Universe based on observations of nearby galaxies like the Milky Way.
265
If the finding that the mass of the halo is comparable to the mass of the Milky Way is confirmed, it could be the identity of the missing baryons around the Milky Way.
265
Formation
Main article:
Galaxy formation and evolution
History
galaxy color–magnitude diagram
showing the red sequence (old galaxies, typically elliptical galaxies), the green valley (where the Milky Way is believed to be in), and the blue cloud (young galaxies, typically spiral galaxies).
The Milky Way began as one or several small overdensities in the mass distribution in the
Universe
shortly after the
Big Bang
13.61 billion years ago.
266
267
268
Some of these overdensities were the seeds of globular clusters in which the oldest remaining stars in what is now the Milky Way formed. Nearly half the matter in the Milky Way may have come from other distant galaxies.
266
These stars and clusters now comprise the stellar halo of the Milky Way. Within a few billion years of the birth of the first stars, the mass of the Milky Way was large enough so that it was spinning relatively quickly. Due to
conservation of angular momentum
, this led the gaseous interstellar medium to collapse from a roughly spheroidal shape to a disk. Therefore, later generations of stars formed in this spiral disk. Most younger stars, including the Sun, are observed to be in the disk.
269
270
Since the first stars began to form, the Milky Way has grown through both
galaxy mergers
(particularly early in the Milky Way's growth) and accretion of gas directly from the Galactic halo.
270
The Milky Way is currently accreting material from several small galaxies, including two of its largest satellite galaxies, the
Large
and
Small
Magellanic Clouds, through the
Magellanic Stream
. Direct accretion of gas is observed in
high-velocity clouds
like the
Smith Cloud
271
272
Cosmological simulations indicate that, 11 billion years ago, it merged with a particularly large galaxy that has been labeled the
Kraken
273
274
Properties of the Milky Way such as stellar mass,
angular momentum
, and
metallicity
in its outermost regions suggest it has undergone no mergers with large galaxies in the last 10 billion years. This lack of recent major mergers is unusual among similar spiral galaxies. Its neighbour the Andromeda Galaxy appears to have a more typical history shaped by more recent mergers with relatively large galaxies.
275
276
According to recent studies, the Milky Way as well as the Andromeda Galaxy lie in what in the
galaxy color–magnitude diagram
is known as the "green valley", a region populated by galaxies in transition from the "blue cloud" (galaxies actively forming new stars) to the "red sequence" (galaxies that lack star formation). Star-formation activity in green valley galaxies is slowing as they run out of star-forming gas in the interstellar medium. In simulated galaxies with similar properties, star formation will typically have been extinguished within about five billion years from now, even accounting for the expected, short-term increase in the rate of star formation due to the collision between both the Milky Way and the Andromeda Galaxy.
277
Measurements of other galaxies similar to the Milky Way suggest it is among the reddest and brightest spiral galaxies that are still forming new stars and it is just slightly bluer than the bluest red sequence galaxies.
278
Age and cosmological history
Comparison of the night sky with the night sky of a hypothetical planet within the Milky Way 10 billion years ago, at an age of about 3.6 billion years and 5 billion years before the Sun formed.
279
Globular clusters are among the oldest objects in the Milky Way, which thus set a lower limit on the age of the Milky Way. The ages of individual stars in the Milky Way can be estimated by measuring the abundance of long-lived
radioactive elements
such as
thorium-232
and
uranium-238
, then comparing the results to estimates of their original abundance, a technique called
nucleocosmochronology
. These yield values of about
12.5 ± 3 billion years
for
CS 31082-001
280
and
13.8 ± 4 billion years
for
BD +17° 3248
281
Once a
white dwarf
is formed, it begins to undergo radiative cooling and the surface temperature steadily drops. By measuring the temperatures of the coolest of these white dwarfs and comparing them to their expected initial temperatures, an age estimate can be made. With this technique, the age of the globular cluster M4 was estimated as
12.7 ± 0.7 billion years
. Age estimates of the oldest of these clusters give a best fit estimate of 12.6 billion years, and a 95% confidence upper limit of 16 billion years.
282
In November 2018, astronomers reported the discovery of one of the oldest stars in the universe. About 13.5 billion-years-old,
2MASS J18082002-5104378 B
is a tiny ultra metal-poor (UMP) star made almost entirely of materials released from the
Big Bang
, and is possibly one of the first stars. The discovery of the star in the Milky Way
Galaxy
suggests that the galaxy may be at least 3 billion years older than previously thought.
283
284
285
Several individual stars have been found in the Milky Way's halo with measured ages very close to the 13.80-billion-year
age of the Universe
. In 2007, a star in the galactic halo,
HE 1523-0901
, was estimated to be about 13.2 billion years old. As the oldest known object in the Milky Way at that time, this measurement placed a lower limit on the age of the Milky Way.
286
This estimate was made using the UV-Visual Echelle Spectrograph of the
Very Large Telescope
to
measure
the relative strengths of
spectral lines
caused by the presence of
thorium
and other
elements
created by the
R-process
. The line strengths yield abundances of different elemental
isotopes
, from which an estimate of the age of the star can be derived using
nucleocosmochronology
286
Another star,
HD 140283
, has been estimated at either 13.7 ± 0.7 billion years, 12.2 ± 0.6 billion years,
287
or 12.0 ± 0.5 billion years.
288
According to observations utilizing
adaptive optics
to correct for Earth's atmospheric distortion, stars in the galaxy's bulge date to about 12.8 billion years old.
289
The age of stars in the galactic
thin disk
has also been estimated using nucleocosmochronology. Measurements of thin disk stars yield an estimate that the thin disk formed 8.8 ± 1.7 billion years ago. These measurements suggest there was a hiatus of almost 5 billion years between the formation of the
galactic halo
and the thin disk.
290
Recent analysis of the chemical signatures of thousands of stars suggests that stellar formation might have dropped by an order of magnitude at the time of disk formation, 10 to 8 billion years ago, when interstellar gas was too hot to form new stars at the same rate as before.
291
The satellite galaxies surrounding the Milky Way are not randomly distributed but seem to be the result of a breakup of some larger system producing a ring structure 500,000 light-years in diameter and 50,000 light-years wide.
292
Close encounters between galaxies, like that expected in 4 billion years with the Andromeda Galaxy, can rip off huge tails of gas, which, over time can coalesce to form dwarf galaxies in a ring at an arbitrary angle to the main disc.
293
Intergalactic neighborhood
A diagram of the galaxies in the
Local Group
relative to the Milky Way
The position of the Local Group within the
Laniakea Supercluster
Main article:
Local Group
The Milky Way and the
Andromeda Galaxy
are a
binary system
of giant spiral galaxies belonging to a group of 50 closely bound galaxies known as the
Local Group
, surrounded by a Local Void, itself being part of the
Local Sheet
294
and in turn the
Virgo Supercluster
. Surrounding the Virgo Supercluster are a number of
voids
, devoid of many galaxies, the Microscopium Void to the "north", the Sculptor Void to the "left", the
Boötes Void
to the "right" and the Canes-Major Void to the "south". These voids change shape over time, creating filamentous structures of galaxies. The Virgo Supercluster, for instance, is being drawn towards the
Great Attractor
295
which in turn forms part of a greater structure, called
Laniakea
296
Two smaller galaxies and a number of
dwarf galaxies
in the Local Group orbit the Milky Way. The largest of these is the
Large Magellanic Cloud
with a diameter of 32,200 light-years.
297
It has a close companion, the
Small Magellanic Cloud
. The
Magellanic Stream
is a stream of neutral
hydrogen
gas extending from these two small galaxies across 100° of the sky. The stream is thought to have been dragged from the Magellanic Clouds in tidal interactions with the Milky Way.
298
Some of the
dwarf galaxies orbiting the Milky Way
are
Canis Major Dwarf
(the closest),
Sagittarius Dwarf Elliptical Galaxy
Ursa Minor Dwarf
Sculptor Dwarf
Sextans Dwarf
Fornax Dwarf
, and
Leo I Dwarf
299
The smallest dwarf galaxies of the Milky Way are only 500 light-years in diameter. These include
Carina Dwarf
Draco Dwarf
, and
Leo II Dwarf
. There may still be undetected dwarf galaxies that are dynamically bound to the Milky Way, which is supported by the detection of nine new satellites of the Milky Way in a relatively small patch of the night sky in 2015.
299
There are some dwarf galaxies that have already been absorbed by the Milky Way, such as the progenitor of
Omega Centauri
300
In 2005
301
with further confirmation in 2012
302
researchers reported that most satellite galaxies of the Milky Way lie in a very large disk and orbit in the same direction. This came as a surprise: according to standard cosmology, satellite galaxies should form in dark matter halos, and they should be widely distributed and moving in random directions. This discrepancy is still not explained.
303
In January 2006, researchers reported that the heretofore unexplained warp in the disk of the Milky Way has now been mapped and found to be a ripple or vibration set up by the Large and Small Magellanic Clouds as they orbit the Milky Way, causing vibrations when they pass through its edges. Previously, these two galaxies, at around 2% of the mass of the Milky Way, were considered too small to influence the Milky Way. However, in a computer model, the movement of these two galaxies creates a dark matter wake that amplifies their influence on the larger Milky Way.
304
Current measurements suggest the Andromeda Galaxy is approaching the Milky Way at 100 to 140 km/s (220,000 to 310,000 mph). In 4.3 billion years, there may be an
Andromeda–Milky Way collision
, depending on the importance of unknown lateral components to the galaxies' relative motion. If they collide, the chance of individual
stars colliding
with each other is extremely low,
305
but instead the two galaxies will merge to form a single
elliptical galaxy
or perhaps a large
disk galaxy
306
over the course of about six billion years.
307
See also
solar system portal
outer space portal
astronomy portal
Baade's Window
Galactic astronomy
Galactic Center GeV excess
Oort constants
Notes
The distance towards its
center
Sagittarius A*
).
This is the diameter measured using the D
25
standard. It has been recently suggested that there is a presence of disk stars beyond this diameter, although it is not clear how much of this influences the surface brightness profile.
11
Some authors use the term
Milky Way
to refer exclusively to the band of light that the galaxy forms in the night sky, while the galaxy receives the full name
Milky Way Galaxy
. See for example Laustsen et al.,
23
Pasachoff,
24
Jones,
25
van der Kruit,
26
and Hodge et al.
27
See also
Bortle Dark-Sky Scale
The bright center of the galaxy is located in the constellation
Sagittarius
. From Sagittarius, the hazy band of white light appears to pass westward through the constellations of
Scorpius
Ara
Norma
Triangulum Australe
Circinus
Centaurus
Musca
Crux
Carina
Vela
Puppis
Canis Major
Monoceros
Orion
and
Gemini
Taurus
, to the
galactic anticenter
in
Auriga
. From there, it passes through
Perseus
Andromeda
Cassiopeia
Cepheus
and
Lacerta
Cygnus
Vulpecula
Sagitta
Aquila
Ophiuchus
Scutum
, and back to
Sagittarius
These estimates are very uncertain, as most non-star objects are difficult to detect; for example, black hole estimates range from ten million to one billion.
172
173
Karachentsev et al. give a
blue
absolute magnitude of −20.8. Combined with a
color index
of 0.55 estimated
here
, an absolute visual magnitude of −21.35 (−20.8 − 0.55 = −21.35) is obtained. Determining the absolute magnitude of the Milky Way is very difficult, because Earth is inside it.
For a photo see:
"Sagittarius A*: Milky Way monster stars in cosmic reality show"
Chandra X-ray Observatory
. Center for Astrophysics | Harvard & Smithsonian. January 6, 2003.
Archived
from the original on March 17, 2008
. Retrieved
May 20,
2012
References
Petrov, L.; Kovalev, Y. Y.; Fomalont, E. B.; Gordon, D. (2011). "The Very Long Baseline Array Galactic Plane Survey—VGaPS".
The Astronomical Journal
142
(2): 35.
arXiv
1101.1460
Bibcode
2011AJ....142...35P
doi
10.1088/0004-6256/142/2/35
ISSN
0004-6256
S2CID
121762178
Event Horizon Telescope Collaboration; et al. (2022).
"First Sagittarius A* Event Horizon Telescope Results. VI. Testing the Black Hole Metric"
The Astrophysical Journal
930
(2): L17.
arXiv
2311.09484
Bibcode
2022ApJ...930L..17E
doi
10.3847/2041-8213/ac6756
S2CID
248744741
Banerjee, Indrani; Sau, Subhadip; SenGupta, Soumitra (2022). "Do shadows of SGR A* and M87* indicate black holes with a magnetic monopole charge?".
arXiv
2207.06034
gr-qc
].
Abuter, R.; et al. (2019). "A geometric distance measurement to the Galactic center black hole with 0.3% uncertainty".
Astronomy & Astrophysics
625
: L10.
arXiv
1904.05721
Bibcode
2019A&A...625L..10G
doi
10.1051/0004-6361/201935656
S2CID
119190574
Gerhard, O. (2002). "Mass distribution in our Galaxy".
Space Science Reviews
100
(1/4):
129–
138.
arXiv
astro-ph/0203110
Bibcode
2002SSRv..100..129G
doi
10.1023/A:1015818111633
S2CID
42162871
Frommert, Hartmut; Kronberg, Christine (August 26, 2005).
"Classification of the Milky Way Galaxy"
SEDS
Archived
from the original on May 31, 2015
. Retrieved
May 30,
2015
Starr, Michelle (March 8, 2019).
"The Latest Calculation of Milky Way's Mass Just Changed What We Know About Our Galaxy"
ScienceAlert.com
Archived
from the original on March 8, 2019
. Retrieved
March 8,
2019
Watkins, Laura L.; et al. (February 2, 2019).
"Evidence for an Intermediate-Mass Milky Way from Gaia DR2 Halo Globular Cluster Motions"
The Astrophysical Journal
873
(2): 118.
arXiv
1804.11348
Bibcode
2019ApJ...873..118W
doi
10.3847/1538-4357/ab089f
S2CID
85463973
Kafle, P.R.; Sharma, S.; Lewis, G.F.; Bland-Hawthorn, J. (2012). "Kinematics of the Stellar Halo and the Mass Distribution of the Milky Way Using Blue Horizontal Branch Stars".
The Astrophysical Journal
761
(2): 17.
arXiv
1210.7527
Bibcode
2012ApJ...761...98K
doi
10.1088/0004-637X/761/2/98
S2CID
119303111
Goodwin, S. P.; Gribbin, J.; Hendry, M. A. (August 1998). "The relative size of the Milky Way".
The Observatory
118
201–
208.
Bibcode
1998Obs...118..201G
López-Corredoira, M.; Allende Prieto, C.; Garzón, F.; Wang, H.; Liu, C.; Deng, L. (April 9, 2018).
"Disk stars in the Milky Way detected beyond 25 kpc from its center"
Astronomy & Astrophysics
612
: L8.
arXiv
1804.03064
Bibcode
2018A&A...612L...8L
doi
10.1051/0004-6361/201832880
S2CID
59933365
Frommert, H.; Kronberg, C. (August 25, 2005).
"The Milky Way Galaxy"
. SEDS. Archived from
the original
on May 12, 2007
. Retrieved
May 9,
2007
Wethington, Nicholos.
"How Many Stars are in the Milky Way?"
Archived
from the original on March 27, 2010
. Retrieved
April 9,
2010
Lian, Jianhui; Zasowski, Gail; Chen, Bingqiu; Imig, Julie; Wang, Tao; Boardman, Nicholas; Liu, Xiaowei (June 28, 2024),
The size of the Milky Way galaxy
arXiv
2406.05604
Kalberla, Peter M.W.; Kerp, Jürgen (September 1, 2009).
"The H
Distribution of the Milky Way"
Annual Review of Astronomy and Astrophysics
47
(1):
27–
61.
Bibcode
2009ARA&A..47...27K
doi
10.1146/annurev-astro-082708-101823
ISSN
0066-4146
. Retrieved
October 23,
2025
Bland-Hawthorn, Joss; Gerhard, Ortwin (2016). "The Galaxy in Context: Structural, Kinematic, and Integrated Properties".
Annual Review of Astronomy and Astrophysics
54
529–
596.
arXiv
1602.07702
Bibcode
2016ARA&A..54..529B
doi
10.1146/annurev-astro-081915-023441
S2CID
53649594
Karachentsev, Igor.
"Double Galaxies § 7.1"
ned.ipac.caltech.edu
. Izdatel'stvo Nauka.
Archived
from the original on March 4, 2016
. Retrieved
April 5,
2015
"A New Map of the Milky Way"
Scientific American
. April 1, 2020.
Archived
from the original on April 27, 2021
. Retrieved
August 10,
2022
Gerhard, O. (2010). "Pattern speeds in the Milky Way".
arXiv
1003.2489v1
astro-ph.GA
].
Shen, Juntai; Zheng, Xing-Wu (2020). "The bar and spiral arms in the Milky Way: Structure and kinematics".
Research in Astronomy and Astrophysics
20
(10): 159.
arXiv
2012.10130
Bibcode
2020RAA....20..159S
doi
10.1088/1674-4527/20/10/159
S2CID
229005996
Kogut, Alan; et al. (December 10, 1993). "Dipole anisotropy in the COBE differential microwave radiometers first-year sky maps".
The Astrophysical Journal
419
1–
6.
arXiv
astro-ph/9312056
Bibcode
1993ApJ...419....1K
doi
10.1086/173453
S2CID
209835274
Kafle, P.R.; Sharma, S.; Lewis, G.F.; Bland-Hawthorn, J. (2014). "On the Shoulders of Giants: Properties of the Stellar Halo and the Milky Way Mass Distribution".
The Astrophysical Journal
794
(1): 17.
arXiv
1408.1787
Bibcode
2014ApJ...794...59K
doi
10.1088/0004-637X/794/1/59
S2CID
119040135
Laustsen, Svend; Madsen, Claus; West, Richard M. (1987).
Exploring the Southern Sky: a Pictorial Atlas from the European Southern Observatory (ESO)
. Berlin, Heidelberg: Springer. p. 119.
ISBN
978-3-642-61588-7
OCLC
851764943
Pasachoff, Jay M.
(1994).
Astronomy: From the Earth to the Universe
. Harcourt School. p. 500.
ISBN
978-0-03-001667-7
Jones, Barrie William (2008).
The Search for Life Continued: Planets Around Other Stars
. Berlin: Springer. p. 89.
ISBN
978-0-387-76559-4
OCLC
288474262
Kruit, Pieter C. van der (2019).
Jan Hendrik Oort: Master of the Galactic System
. Cham, Switzerland: Springer. pp. 65, 717.
ISBN
978-3-030-17801-7
OCLC
1110483488
Hodge, Paul W.
; et al. (October 13, 2020).
"Milky Way Galaxy"
Encyclopædia Britannica
Archived
from the original on January 19, 2022
. Retrieved
April 24,
2022
Croswell, Ken (March 23, 2020).
"Astronomers have found the edge of the Milky Way at last"
ScienceNews
Archived
from the original on March 24, 2020
. Retrieved
March 27,
2020
Dearson, Alis J. (2020).
"The Edge of the Galaxy"
Monthly Notices of the Royal Astronomical Society
496
(3):
3929–
3942.
arXiv
2002.09497
Bibcode
2020MNRAS.496.3929D
doi
10.1093/mnras/staa1711
S2CID
211259409
"Laniakea: Our home supercluster"
. YouTube. September 3, 2014.
Archived
from the original on September 4, 2014.
Tully, R. Brent; et al. (September 4, 2014). "The Laniakea supercluster of galaxies".
Nature
513
(7516):
71–
73.
arXiv
1409.0880
Bibcode
2014Natur.513...71T
doi
10.1038/nature13674
PMID
25186900
S2CID
205240232
"Milky Way"
BBC
. Archived from
the original
on March 2, 2012.
"How Many Stars in the Milky Way?"
NASA Blueshift
Archived
from the original on January 25, 2016.
Cassan, A.; et al. (January 11, 2012). "One or more bound planets per Milky Way star from microlensing observations".
Nature
481
(7380):
167–
169.
arXiv
1202.0903
Bibcode
2012Natur.481..167C
doi
10.1038/nature10684
PMID
22237108
S2CID
2614136
"100 Billion Alien Planets Fill Our Milky Way Galaxy: Study"
Space.com
. January 2, 2013. Archived from
the original
on January 3, 2013
. Retrieved
January 3,
2013
Gillessen, Stefan; Plewa, Philipp; Eisenhauer, Frank; Sari, Re'em; Waisberg, Idel; Habibi, Maryam; Pfuhl, Oliver; George, Elizabeth; Dexter, Jason; von Fellenberg, Sebastiano; Ott, Thomas; Genzel, Reinhard (November 28, 2016).
"An Update on Monitoring Stellar Orbits in the Galactic Center"
The Astrophysical Journal
837
(1): 30.
arXiv
1611.09144
Bibcode
2017ApJ...837...30G
doi
10.3847/1538-4357/aa5c41
S2CID
119087402
Overbye, Dennis
(January 31, 2022).
"An Electrifying View of the Heart of the Milky Way – A new radio-wave image of the center of our galaxy reveals all the forms of frenzy that a hundred million or so stars can get up to"
The New York Times
Archived
from the original on January 31, 2022
. Retrieved
February 1,
2022
Heyood, I.; et al. (January 28, 2022).
"The 1.28 GHz MeerKAT Galactic Center Mosaic"
The Astrophysical Journal
925
(2): 165.
arXiv
2201.10541
Bibcode
2022ApJ...925..165H
doi
10.3847/1538-4357/ac449a
S2CID
246275657
Bond, H.E.; Nelan, E. P.; VandenBerg, D. A.; Schaefer, G. H.; Harmer, D. (February 13, 2013). "HD 140283: A Star in the Solar Neighborhood that Formed Shortly After the Big Bang".
The Astrophysical Journal
765
(1): L12.
arXiv
1302.3180
Bibcode
2013ApJ...765L..12B
doi
10.1088/2041-8205/765/1/L12
S2CID
119247629
"Milky Way Galaxy: Facts About Our Galactic Home"
Space.com
. Archived from
the original
on March 21, 2017
. Retrieved
April 8,
2017
Shapley, H.; Curtis, H. D. (1921). "The Scale of the Universe".
Bulletin of the National Research Council
(11):
171–
217.
Bibcode
1921BuNRC...2..171S
Brown, William P. (2010).
The Seven Pillars of Creation: The Bible, Science, and the Ecology of Wonder
. Oxford, England: Oxford University Press. p. 25.
ISBN
978-0-19-973079-7
Archived
from the original on March 26, 2023
. Retrieved
April 24,
2019
MacBeath, Alastair (1999).
Tiamat's Brood: An Investigation Into the Dragons of Ancient Mesopotamia
. Dragon's Head. p. 41.
ISBN
978-0-9524387-5-5
Archived
from the original on March 26, 2023
. Retrieved
April 24,
2019
James, E. O. (1963).
The Worship of the Sky-God: A Comparative Study in Semitic and Indo-European Religion
. Jordan Lectures in Comparative Religion. London, England: University of London Press. pp. 24, 27f.
Lambert, W. G. (1964). "E. O. James: The worship of the Skygod: A comparative study in Semitic and Indo-European religion. (School of Oriental and African Studies, University of London. Jordan Lectures in Comparative Religion, vi.) viii, 175 pp. London: University of London, the Athlone Press, 1963. 25s".
Bulletin of the School of Oriental and African Studies
27
(1). London, England: University of London:
157–
158.
doi
10.1017/S0041977X00100345
Waller, William H.;
Hodge, Paul W.
(2003).
Galaxies and the Cosmic Frontier
Harvard University Press
ISBN
978-0-674-01079-6
"Myths about the Milky Way"
judy-volker.com
Archived
from the original on July 1, 2022
. Retrieved
March 21,
2022
Leeming, David Adams (1998).
Mythology: The Voyage of the Hero
(Third ed.). Oxford, England: Oxford University Press. p. 44.
ISBN
978-0-19-511957-2
Archived
from the original on March 26, 2023
. Retrieved
April 24,
2019
Pache, Corinne Ondine (2010).
"Hercules"
. In Gargarin, Michael;
Fantham, Elaine
(eds.).
Ancient Greece and Rome
. Vol. 1: Academy-Bible. Oxford, England: Oxford University Press. p. 400.
ISBN
978-0-19-538839-8
Archived
from the original on March 26, 2023
. Retrieved
April 24,
2019
Harper, Douglas.
"galaxy"
Online Etymology Dictionary
. Retrieved
May 20,
2012
{{
cite web
}}
: CS1 maint: deprecated archival service (
link
Jankowski, Connie (2010).
Pioneers of Light and Sound
. Compass Point Books. p. 6.
ISBN
978-0-7565-4306-8
Archived
from the original on November 20, 2016.
Simpson, John; Weiner, Edmund, eds. (March 30, 1989).
The Oxford English Dictionary
(2nd ed.). Oxford University Press.
ISBN
978-0-19-861186-8
See the entries for "Milky Way" and "galaxy".
Eratosthenes (1997). Condos, Theony (ed.).
Star Myths of the Greeks and Romans: A Sourcebook Containing the Constellations of Pseudo-Eratosthenes and the Poetic Astronomy of Hyginus
. Red Wheel/Weiser.
ISBN
978-1-890482-93-0
Archived
from the original on November 20, 2016.
Harper, Douglas.
"galaxy"
Online Etymology Dictionary
Archived
from the original on November 17, 2011
. Retrieved
November 11,
2011
^ Sauer, EGF (July 1971). "Celestial Rotation and Stellar Orientation in Migratory Warblers". Science 30: 459–461.
"Reconciliation"
Adelaide City Council
. Archived from
the original
on July 12, 2019
. Retrieved
February 26,
2020
Mandow, Rami (May 3, 2021).
"Moonhack – Coding the Story of the Emu in the Sky"
Space Australia
. Retrieved
June 5,
2022
Macleod, Fiona
(1911).
Where the forest murmurs
. New York: Duffield & Company. Chapter 21:
Milky Way
. Archived from
the original
on February 17, 2007.
"The Pilgrim's Way: El Camino de Santiago"
. Archived from
the original
on December 17, 2006
. Retrieved
January 6,
2007
Harutyunyan, Hayk (August 29, 2003).
"The Armenian name of the Milky Way"
ArAS News
. Armenian Astronomical Society (ArAS). Archived from
the original
on April 29, 2006
. Retrieved
August 10,
2009
Repedzic, Aleksandar; Djermanovic, Andjela.
"Kumova slama (Mlečni put)"
Etnolog blog (attributed to Mitološki rečnik 1970 by Š. Kulišić, P. Ž. Petrović i N. Pantelić)
. Retrieved
January 20,
2026
Bogle, Joanna (September 16, 2011).
"A Pilgrimage to Walsingham, 'England's Nazareth'
National Catholic Register
. EWTN
. Retrieved
November 13,
2013
Pasachoff, Jay M.
(1994).
Astronomy: From the Earth to the Universe
. Harcourt School. p. 500.
ISBN
978-0-03-001667-7
Rey, H. A. (1976).
The Stars
. Houghton Mifflin Harcourt. p.
145
ISBN
978-0-395-24830-0
Pasachoff, Jay M.; Filippenko, Alex (2013).
The Cosmos: Astronomy in the New Millennium
. Cambridge University Press. p. 384.
ISBN
978-1-107-68756-1
Archived
from the original on March 26, 2023
. Retrieved
December 18,
2016
Crossen, Craig (July 2013). "Observing the Milky Way, part I: Sagittarius & Scorpius".
Sky & Telescope
126
(1): 24.
Bibcode
2013S&T...126a..24C
Urton, Gary
(1981).
At the Crossroads of the Earth and the Sky: An Andean Cosmology
. Latin American Monographs. Vol. 55. Austin: Univ. of Texas Pr. pp.
102–
4,
109–
11.
ISBN
0-292-70349-X
Starr, Michelle (July 14, 2020).
"A Giant 'Wall' of Galaxies Has Been Found Stretching Across The Universe"
ScienceAlert
Archived
from the original on February 5, 2021
. Retrieved
May 5,
2022
Crumey, Andrew (2014).
"Human contrast threshold and astronomical visibility"
Monthly Notices of the Royal Astronomical Society
442
(3):
2600–
2619.
arXiv
1405.4209
Bibcode
2014MNRAS.442.2600C
doi
10.1093/mnras/stu992
S2CID
119210885
Steinicke, Wolfgang; Jakiel, Richard (2007).
Galaxies and how to observe them
. Astronomers' observing guides. Springer. p.
94
ISBN
978-1-85233-752-0
Falchi, Fabio; Cinzano, Pierantonio; Duriscoe, Dan; Kyba, Christopher C. M.; Elvidge, Christopher D.; Baugh, Kimberly; Portnov, Boris A.; Rybnikova, Nataliya A.; Furgoni, Riccardo (June 1, 2016).
"The new world atlas of artificial night sky brightness"
Science Advances
(6) e1600377.
arXiv
1609.01041
Bibcode
2016SciA....2E0377F
doi
10.1126/sciadv.1600377
ISSN
2375-2548
PMC
4928945
PMID
27386582
Miller, James (November 14, 2015).
"Which Constellations Can Be Seen Along The Milky Way?"
. Retrieved
August 13,
2024
"Galactic Plane | COSMOS"
astronomy.swin.edu.au
. Retrieved
July 9,
2025
Aristotle with W. D. Ross, ed.,
The Works of Aristotle
... (Oxford, England: Clarendon Press, 1931), vol. III,
Meteorologica
, E. W. Webster, trans., Book 1, Part 8,
pp. 39–40
Archived
April 11, 2016, at the
Wayback Machine
: "(2) Anaxagoras, Democritus, and their schools say that the milky way is the light of certain stars ... shaded by the earth from the sun's rays."
"What does your image show"
mo-www.harvard.edu
Archived
from the original on March 15, 2023
. Retrieved
October 20,
2022
Montada, Josep Puig (September 28, 2007).
"Ibn Bajja"
Stanford Encyclopedia of Philosophy
. Retrieved
July 11,
2008
{{
cite encyclopedia
}}
: CS1 maint: deprecated archival service (
link
Aristotle (1931).
Works
. Translated by Ross, William David; Smith, John Alexander. Oxford: Clarendon Press. p. 345.
Heidarzadeh, Tofigh (2008).
A history of physical theories of comets, from Aristotle to Whipple
. Springer. pp.
23
–25.
ISBN
978-1-4020-8322-8
O'Connor, John J.;
Robertson, Edmund F.
"Abu Rayhan Muhammad ibn Ahmad al-Biruni"
MacTutor History of Mathematics Archive
University of St Andrews
Ragep, Jamil (1993).
Nasir al-Din al-Tusi's Memoir on Astronomy
al-Tadhkira fi 'ilm al-hay' a
. New York: Springer-Verlag. p. 129.
Livingston, John W. (1971). "Ibn Qayyim al-Jawziyyah: A Fourteenth Century Defense against Astrological Divination and Alchemical Transmutation".
Journal of the American Oriental Society
91
(1): 96–103 [99].
doi
10.2307/600445
JSTOR
600445
Galileo Galilei,
Sidereus Nuncius
(Venice: Thomas Baglioni, 1610),
pp. 15–16
Archived
March 16, 2016, at the
Wayback Machine
English translation: Galileo Galilei with Edward Stafford Carlos, trans.,
The Sidereal Messenger
(London: Rivingtons, 1880),
pp. 42–43
Archived
December 2, 2012, at the
Wayback Machine
O'Connor, J. J.; Robertson, E. F. (November 2002).
"Galileo Galilei"
. University of St. Andrews
. Retrieved
January 8,
2007
{{
cite web
}}
: CS1 maint: deprecated archival service (
link
Thomas Wright,
An Original Theory or New Hypothesis of the Universe
(London, England: H. Chapelle, 1750).
On page 57
Archived
November 20, 2016, at the
Wayback Machine
, Wright stated that despite their mutual gravitational attraction, the stars in the constellations do not collide because they are in orbit, so centrifugal force keeps them separated: "centrifugal force, which not only preserves them in their orbits, but prevents them from rushing all together, by the common universal law of gravity, ..."
On page 48
Archived
November 20, 2016, at the
Wayback Machine
, Wright stated that the form of the Milky Way is a ring: "the stars are not infinitely dispersed and distributed in a promiscuous manner throughout all the mundane space, without order or design, ... this phænomenon [is] no other than a certain effect arising from the observer's situation, ... To a spectator placed in an indefinite space, ... it [i.e. the Milky Way (
Via Lactea
)] [is] a vast ring of stars ..."
On page 65
Archived
November 20, 2016, at the
Wayback Machine
, Wright speculated that the central body of the Milky Way, around which the rest of the galaxy revolves, might not be visible to us: "the central body A, being supposed as
incognitum
[i.e. an unknown], without [i.e. outside of] the finite view; ..."
On page 73
Archived
November 20, 2016, at the
Wayback Machine
, Wright called the Milky Way the
Vortex Magnus
(the great whirlpool) and estimated its diameter to be 8.64×10
12
miles (13.9×10
12
km).
On page 33
Archived
November 20, 2016, at the
Wayback Machine
, Wright speculated that there are a vast number of inhabited planets in the galaxy: "therefore we may justly suppose, that so many radiant bodies [i.e. stars] were not created barely to enlighten an infinite void, but to ... display an infinite shapeless universe, crowded with myriads of glorious worlds, all variously revolving round them; and ... with an inconceivable variety of beings and states, animate ..."
Immanuel Kant,
Allgemeine Naturgeschichte und Theorie des Himmels
Archived
November 20, 2016, at the
Wayback Machine
General Natural History and Theory of Heaven
], (Koenigsberg and Leipzig, (Germany): Johann Friederich Petersen, 1755).
On pages 2–3, Kant acknowledged his debt to Thomas Wright:
"Dem Herrn Wright von Durham, einen Engeländer, war es vorbehalten, einen glücklichen Schritt zu einer Bemerkung zu thun, welche von ihm selber zu keiner gar zu tüchtigen Absicht gebraucht zu seyn scheinet, und deren nützliche Anwendung er nicht genugsam beobachtet hat. Er betrachtete die Fixsterne nicht als ein ungeordnetes und ohne Absicht zerstreutes Gewimmel, sondern er fand eine systematische Verfassung im Ganzen, und eine allgemeine Beziehung dieser Gestirne gegen einen Hauptplan der Raume, die sie einnehmen."
("To Mr. Wright of Durham, an Englishman, it was reserved to take a happy step towards an observation, which seemed, to him and to no one else, to be needed for a clever idea, the exploitation of which he has not studied sufficiently. He regarded the fixed stars not as a disorganized swarm that was scattered without a design; rather, he found a systematic shape in the whole, and a general relation between these stars and the principal plane of the space that they occupy.")
Kant (1755),
pages xxxiii–xxxvi of the Preface (
Vorrede
Archived
November 20, 2016, at the
Wayback Machine
"Ich betrachtete die Art neblichter Sterne, deren Herr von Maupertuis in der Abhandlung von der Figur der Gestirne gedenket, und die die Figur von mehr oder weniger offenen Ellipsen vorstellen, und versicherte mich leicht, daß sie nichts anders als eine Häufung vieler Fixsterne seyn können. Die jederzeit abgemessene Rundung dieser Figuren belehrte mich, daß hier ein unbegreiflich zahlreiches Sternenheer, und zwar um einen gemeinschaftlichen Mittelpunkt, müste geordnet seyn, weil sonst ihre freye Stellungen gegen einander, wohl irreguläre Gestalten, aber nicht abgemessene Figuren vorstellen würden. Ich sahe auch ein: daß sie in dem System, darinn sie sich vereinigt befinden, vornemlich auf eine Fläche beschränkt seyn müßten, weil sie nicht zirkelrunde, sondern elliptische Figuren abbilden, und daß sie wegen ihres blassen Lichts unbegreiflich weit von uns abstehen."
("I considered the type of nebulous stars, which Mr. de Maupertuis considered in his treatise on the shape of stars, and which present the figures of more or less open ellipses, and I readily assured myself, that they could be nothing else than a cluster of fixed stars. That these figures always measured round informed me that here an inconceivably numerous host of stars, [which were clustered] around a common center, must be orderly, because otherwise their free positions among each other would probably present irregular forms, not measurable figures. I also realized: that in the system in which they find themselves bound, they must be restricted primarily to a plane, because they display not circular, but elliptical figures, and that on account of their faint light, they are located inconceivably far from us.")
Evans, J. C. (November 24, 1998).
"Our Galaxy"
. George Mason University
. Retrieved
January 4,
2007
{{
cite web
}}
: CS1 maint: deprecated archival service (
link
The term
Weltinsel
(world island) appears nowhere in Kant's book of 1755. The term first appeared in 1850, in the third volume of von Humboldt's
Kosmos
: Alexander von Humboldt,
Kosmos
, vol. 3 (Stuttgart & Tübingen, (Germany): J. G. Cotta, 1850), pp. 187, 189.
From p. 187
Archived
November 20, 2016, at the
Wayback Machine
"Thomas Wright von Durham, Kant, Lambert und zuerst auch William Herschel waren geneigt die Gestalt der Milchstraße und die scheinbare Anhäufung der Sterne in derselben als eine Folge der abgeplatteten Gestalt und ungleichen Dimensionen der
Weltinsel
(Sternschict) zu betrachten, in welche unser Sonnensystem eingeschlossen ist."
("Thomas Wright of Durham, Kant, Lambert and at first also William Herschel were inclined to regard the shape of the Milky Way and the apparent clustering of stars in it as a consequence of the oblate shape and unequal dimensions of the
world island
(star stratum), in which our solar system is included.)
In the English translation – Alexander von Humboldt with
E. C. Otté
, trans.,
Cosmos
... (New York City: Harper & Brothers, 1897), vols. 3–5. see
p. 147
Archived
November 6, 2018, at the
Wayback Machine
William Herschel (1785), "On the Construction of the Heavens",
Philosophical Transactions of the Royal Society of London
75
: 213–266. Herschel's diagram of the Milky Way appears immediately after the article's last page. See:
Google Books
Archived
November 20, 2016, at the
Wayback Machine
The Royal Society of London
Archived
April 6, 2016, at the
Wayback Machine
Abbey, Lenny.
"The Earl of Rosse and the Leviathan of Parsontown"
. The Compleat Amateur Astronomer. Archived from
the original
on May 19, 2013
. Retrieved
January 4,
2007
See:
Rosse revealed the spiral structure of
Whirlpool Galaxy
(M51) at the 1845 meeting of the British Association for the Advancement of Science. Rosse's illustration of M51 was reproduced in J. P. Nichol's book of 1846.
Rosse, Earl of (1846).
"On the nebula 25 Herschel, or 61 [should read: 51] of Messier's catalogue"
Report of the Fifteenth Meeting of the British Association for the Advancement of Science; Held at Cambridge in June 1845 § Notices and Abstracts of Miscellaneous Communications to the Sections
. Report of the ... Meeting of the British Association for the Advancement of Science (1833): 4.
Archived
from the original on March 10, 2021
. Retrieved
February 17,
2020
Nichol, John Pringle (1846).
Thoughts on Some Important Points Relating to the System of the World
. Edinburgh, Scotland: William Tait. p. 23.
Archived
from the original on March 8, 2021
. Retrieved
February 17,
2020
Rosse's illustration of the Whirlpool Galaxy appears on the plate that immediately precedes p. 23.
South, James (1846).
"Auszug aus einem Berichte über Lord
Rosse's
grosses Telescop, den Sir
James South
in The Times, Nr. 18899, 1845 April 16 bekannt gemacht hat"
[Excerpt from a report about Lord Rosse's great telescope, which Sir James South made known in The Times [of London], no. 18,899, 1845 April 16].
Astronomische Nachrichten
(in German).
23
(536):
113–
118.
doi
10.1002/asna.18460230802
Archived
from the original on March 8, 2021
. Retrieved
February 17,
2020
On March 5, 1845, Rosse observed M51, the
Whirlpool Galaxy
. From column 115: "The most popularly known nebulæ observed this night were the ring nebulæ in the Canes Venatici, or the 51st of
Messier's
catalogue, which was resolved into stars with a magnifying power of 548".
Robinson, T. R. (1845).
"On Lord Rosse's telescope"
Proceedings of the Royal Irish Academy
(50):
114–
133.
Archived
from the original on June 10, 2020
. Retrieved
February 17,
2020
Rosse's early observations of nebulae and galaxies are discussed on pp. 127–130.
Rosse, The Earl of (1850).
"Observations on the nebulae"
Philosophical Transactions of the Royal Society of London
140
(140):
499–
514.
doi
10.1098/rstl.1850.0026
Archived
from the original on March 26, 2023
. Retrieved
February 17,
2020
Rosse's illustrations of nebulae and galaxies appear on the plates that immediately precede the article.
Bailey, M. E.; Butler, C. J.; McFarland, J. (April 2005).
"Unwinding the discovery of spiral nebulae"
Astronomy & Geophysics
46
(2):
2.26 –
2.28
doi
10.1111/j.1468-4004.2005.46226.x
See:
Kapteyn, Jacobus Cornelius (1906).
"Statistical methods in stellar astronomy"
. In Rogers, Howard J. (ed.).
Congress of Arts and Science, Universal Exposition, St. Louis, 1904
. Vol. 4. Boston and New York: Houghton, Mifflin and Co. pp.
396–
425.
Archived
from the original on March 8, 2021
. Retrieved
February 6,
2020
From pp. 419–420: "It follows that the one set of the stars must have a systematic motion relative to the other. ... these two main directions of motion must be in reality diametrically opposite."
Kapteyn, J. C. (1905).
"Star streaming"
Report of the Seventy-fifth Meeting of the British Association for the Advancement of Science, South Africa
. Report of the ... Meeting of the British Association for the Advancement of Science (1833):
257–
265.
Archived
from the original on March 8, 2021
. Retrieved
February 6,
2020
See:
Schwarzschild, K. (1907).
"Ueber die Eigenbewegungen der Fixsterne"
[On the proper motions of the fixed stars].
Nachrichten von der Königlichen Gesellschaft der Wissenschaften zu Göttingen (Reports of the Royal Society of Science at Göttingen)
(in German).
614–
632.
Bibcode
1907NWGot...5..614S
Archived
from the original on March 8, 2021
. Retrieved
February 6,
2020
Schwarzschild, K. (1908).
"Ueber die Bestimmung von Vertex und Apex nach der Ellipsoidhypothese aus einer geringeren Anzahl beobachteter Eigenbewegungen"
[On the determination, according to the ellipsoid hypothesis, of the vertex and apex from a small number of observed proper motions].
Nachrichten von der Königlichen Gesellschaft der Wissenschaften zu Göttingen
(in German):
191–
200.
Archived
from the original on March 8, 2021
. Retrieved
February 6,
2020
Curtis, Heber D. (1917).
"Novae in spiral nebulae and the island universe theory"
Publications of the Astronomical Society of the Pacific
29
(171):
206–
207.
Bibcode
1917PASP...29..206C
doi
10.1086/122632
Curtis, H. D.
(1988).
"Novae in spiral nebulae and the Island Universe Theory"
Publications of the Astronomical Society of the Pacific
100
6–
7.
Bibcode
1988PASP..100....6C
doi
10.1086/132128
Weaver, Harold F.
"Robert Julius Trumpler"
. National Academy of Sciences
. Retrieved
January 5,
2007
{{
cite web
}}
: CS1 maint: deprecated archival service (
link
Sandage, Allan
(1989). "Edwin Hubble, 1889–1953".
Journal of the Royal Astronomical Society of Canada
83
(6): 351.
Bibcode
1989JRASC..83..351S
Hubble, E. P.
(1929).
"A spiral nebula as a stellar system, Messier 31"
The Astrophysical Journal
69
103–
158.
Bibcode
1929ApJ....69..103H
doi
10.1086/143167
"New Milky Way Map Is a Spectacular Billion-Star Atlas"
. September 14, 2016. Archived from
the original
on September 15, 2016
. Retrieved
September 15,
2016
"Gaia > Gaia DR1"
www.cosmos.esa.int
Archived
from the original on September 15, 2016
. Retrieved
September 15,
2016
Skibba, Ramin (June 10, 2021).
"A galactic archaeologist digs into the Milky Way's history"
Knowable Magazine
doi
10.1146/knowable-060921-1
S2CID
236290725
Archived
from the original on August 4, 2022
. Retrieved
August 4,
2022
Poggio, E.; Drimmel, R.; Andrae, R.; Bailer-Jones, C. A. L.; Fouesneau, M.; Lattanzi, M. G.; Smart, R. L.; Spagna, A. (2020). "Evidence of a dynamically evolving Galactic warp".
Nature Astronomy
(6):
590–
596.
arXiv
1912.10471
Bibcode
2020NatAs...4..590P
doi
10.1038/s41550-020-1017-3
S2CID
209444772
Overbye, Dennis
(April 19, 2024).
"The Dusty Magnets of the Milky Way"
The New York Times
. Retrieved
April 19,
2024
{{
cite news
}}
: CS1 maint: deprecated archival service (
link
Alves, João; Zucker, Catherine; Goodman, Alyssa A.; Speagle, Joshua S.; Meingast, Stefan; Robitaille, Thomas; Finkbeiner, Douglas P.; Schlafly, Edward F.; Green, Gregory M. (January 7, 2020). "A Galactic-scale gas wave in the Solar Neighborhood".
Nature
578
(7794):
237–
239.
arXiv
2001.08748
Bibcode
2020Natur.578..237A
doi
10.1038/s41586-019-1874-z
PMID
31910431
S2CID
210086520
Boehle, A.; Ghez, A. M.; Schödel, R.; Meyer, L.; Yelda, S.; Albers, S.; Martinez, G. D.; Becklin, E. E.; Do, T.; Lu, J. R.; Matthews, K.; Morris, M. R.; Sitarski, B.; Witzel, G. (October 3, 2016).
"An Improved Distance and Mass Estimate for SGR A* from a Multistar Orbit Analysis"
(PDF)
The Astrophysical Journal
830
(1): 17.
arXiv
1607.05726
Bibcode
2016ApJ...830...17B
doi
10.3847/0004-637X/830/1/17
hdl
10261/147803
S2CID
307657
Archived
(PDF)
from the original on December 2, 2017
. Retrieved
July 31,
2018
Majaess, D. J.; Turner, D. G.; Lane, D. J. (2009).
"Characteristics of the Galaxy according to Cepheids"
Monthly Notices of the Royal Astronomical Society
398
(1):
263–
270.
arXiv
0903.4206
Bibcode
2009MNRAS.398..263M
doi
10.1111/j.1365-2966.2009.15096.x
S2CID
14316644
English, Jayanne
(January 14, 2000).
"Exposing the Stuff Between the Stars"
. Hubble News Desk.
Archived
from the original on July 7, 2007
. Retrieved
May 10,
2007
Mullen, Leslie (May 18, 2001).
"Galactic Habitable Zones"
NAI Features Archive
. Nasa Astrobiology Institute. Archived from
the original
on April 9, 2013
. Retrieved
May 9,
2013
Sundin, M. (2006). "The galactic habitable zone in barred galaxies".
International Journal of Astrobiology
(4):
325–
326.
Bibcode
2006IJAsB...5..325S
doi
10.1017/S1473550406003065
S2CID
122018103
"Magnitude"
. National Solar Observatory – Sacramento Peak. Archived from
the original
on February 6, 2008
. Retrieved
August 9,
2013
Moore, Patrick; Rees, Robin (2014).
Patrick Moore's Data Book of Astronomy
(2nd ed.). Cambridge University Press. p. 4.
ISBN
978-1-139-49522-6
Archived
from the original on February 15, 2017.
Gillman, M.; Erenler, H. (2008).
"The galactic cycle of extinction"
(PDF)
International Journal of Astrobiology
(1): 17.
Bibcode
2008IJAsB...7...17G
CiteSeerX
10.1.1.384.9224
doi
10.1017/S1473550408004047
S2CID
31391193
Archived
(PDF)
from the original on June 1, 2019
. Retrieved
July 31,
2018
Overholt, A. C.; Melott, A. L.; Pohl, M. (2009). "Testing the link between terrestrial climate change and galactic spiral arm transit".
The Astrophysical Journal
705
(2):
L101–
L103.
arXiv
0906.2777
Bibcode
2009ApJ...705L.101O
doi
10.1088/0004-637X/705/2/L101
S2CID
734824
Sparke, Linda S.
; Gallagher, John S. (2007).
Galaxies in the Universe: An Introduction
. Cambridge University Press. p. 90.
ISBN
978-1-139-46238-9
Garlick, Mark Antony (2002).
The Story of the Solar System
. Cambridge University. p.
46
ISBN
978-0-521-80336-6
"Solar System's 'Nose' Found; Aimed at Constellation Scorpius"
. April 8, 2011. Archived from
the original
on September 7, 2015.
Blaauw, A.; et al. (1960), "The new I. A. U. system of galactic coordinates (1958 revision)",
Monthly Notices of the Royal Astronomical Society
121
(2):
123–
131,
Bibcode
1960MNRAS.121..123B
doi
10.1093/mnras/121.2.123
Wilson, Thomas L.; et al. (2009),
Tools of Radio Astronomy
, Springer Science & Business Media,
Bibcode
2009tra..book.....W
ISBN
978-3-540-85121-9
archived
from the original on April 26, 2016
Kiss, Cs; Moór, A.; Tóth, L. V. (April 2004).
"Far-infrared loops in the 2nd Galactic Quadrant"
(PDF)
Astronomy and Astrophysics
418
131–
141.
arXiv
astro-ph/0401303
Bibcode
2004A&A...418..131K
doi
10.1051/0004-6361:20034530
S2CID
7825138
. Retrieved
August 17,
2010
Lampton, M.; et al. (February 1997).
"An All-Sky Catalog of Faint Extreme Ultraviolet Sources"
The Astrophysical Journal Supplement Series
108
(2):
545–
557.
Bibcode
1997ApJS..108..545L
doi
10.1086/312965
van Woerden, Hugo; Strom, Richard G. (June 2006).
"The beginnings of radio astronomy in the Netherlands"
(PDF)
Journal of Astronomical History and Heritage
(1):
3–
20.
Bibcode
2006JAHH....9....3V
doi
10.3724/SP.J.1440-2807.2006.01.01
S2CID
16816839
. Archived from
the original
(PDF)
on September 19, 2010.
Sale, S. E.; et al. (2010).
"The structure of the outer Galactic disc as revealed by IPHAS early A stars"
Monthly Notices of the Royal Astronomical Society
402
(2):
713–
723.
arXiv
0909.3857
Bibcode
2010MNRAS.402..713S
doi
10.1111/j.1365-2966.2009.15746.x
S2CID
12884630
"Dimensions of Galaxies"
ned.ipac.caltech.edu
Archived
from the original on September 27, 2022
. Retrieved
August 22,
2022
Goodwin, S. P.; Gribbin, J.; Hendry, M. A. (April 22, 1997). "The Milky Way is just an average spiral".
arXiv
astro-ph/9704216
Castro-Rodríguez, N.; López-Corredoira, M.; Sánchez-Saavedra, M. L.; Battaner, E. (2002). "Warps and correlations with intrinsic parameters of galaxies in the visible and radio".
Astronomy & Astrophysics
391
(2):
519–
530.
arXiv
astro-ph/0205553
Bibcode
2002A&A...391..519C
doi
10.1051/0004-6361:20020895
S2CID
17813024
Goodwin, S. P.; Gribbin, J.; Hendry, M. A. (April 30, 1997). "New Determination of the Hubble Parameter Using the Principle of Terrestrial Mediocrity".
arXiv
astro-ph/9704289
"How Big is Our Universe: How far is it across the Milky Way?"
NASA-Smithsonian Education Forum on the Structure and Evolution of the Universe, at the Harvard Smithsonian Center for Astrophysics
Archived
from the original on March 5, 2013
. Retrieved
March 13,
2013
Newberg, Heidi Jo; et al. (March 1, 2015). "Rings and Radial Waves in the Disk of the Milky Way".
The Astrophysical Journal
801
(2): 105.
arXiv
1503.00257
Bibcode
2015ApJ...801..105X
doi
10.1088/0004-637X/801/2/105
S2CID
119124338
Mary L. Martialay (March 11, 2015).
"The Corrugated Galaxy – Milky Way May Be Much Larger Than Previously Estimated"
(Press release).
Rensselaer Polytechnic Institute
. Archived from
the original
on March 13, 2015.
Sheffield, Allyson A.; Price-Whelan, Adrian M.; Tzanidakis, Anastasios; Johnston, Kathryn V.; Laporte, Chervin F. P.; Sesar, Branimir (2018).
"A Disk Origin for the Monoceros Ring and A13 Stellar Overdensities"
The Astrophysical Journal
854
(1): 47.
arXiv
1801.01171
Bibcode
2018ApJ...854...47S
doi
10.3847/1538-4357/aaa4b6
S2CID
118932403
David Freeman (May 25, 2018).
"The Milky Way galaxy may be much bigger than we thought"
(Press release).
CNBC
Archived
from the original on August 13, 2018
. Retrieved
August 13,
2018
Elizabeth Howell (July 2, 2018).
"It Would Take 200,000 Years at Light Speed to Cross the Milky Way"
Space.com
Archived
from the original on April 16, 2020
. Retrieved
May 31,
2020
Coffey, Jeffrey.
"How big is the Milky Way?"
Universe Today
. Archived from
the original
on September 24, 2013
. Retrieved
November 28,
2007
Rix, Hans-Walter; Bovy, Jo (2013). "The Milky Way's Stellar Disk".
The Astronomy and Astrophysics Review
21
61.
arXiv
1301.3168
Bibcode
2013A&ARv..21...61R
doi
10.1007/s00159-013-0061-8
S2CID
117112561
Bobylev, V. V.; Baykova, A. T. (August 2023).
"Modern Estimates of the Mass of the Milky Way"
Astronomy Reports
67
(8):
812–
823.
Bibcode
2023ARep...67..812B
doi
10.1134/S1063772923080024
ISSN
1063-7729
Karachentsev, I. D.; Kashibadze, O. G. (2006). "Masses of the local group and of the M81 group estimated from distortions in the local velocity field".
Astrophysics
49
(1):
3–
18.
Bibcode
2006Ap.....49....3K
doi
10.1007/s10511-006-0002-6
S2CID
120973010
Vayntrub, Alina (2000).
"Mass of the Milky Way"
The Physics Factbook
. Archived from
the original
on August 13, 2014
. Retrieved
May 9,
2007
Battaglia, G.; et al. (2005).
"The radial velocity dispersion profile of the Galactic halo: Constraining the density profile of the dark halo of the Milky Way"
Monthly Notices of the Royal Astronomical Society
364
(2):
433–
442.
arXiv
astro-ph/0506102
Bibcode
2005MNRAS.364..433B
doi
10.1111/j.1365-2966.2005.09367.x
S2CID
15562509
Finley, Dave; Aguilar, David (January 5, 2009).
"Milky Way a Swifter Spinner, More Massive, New Measurements Show"
(Press release). National Radio Astronomy Observatory. Archived from
the original
on August 8, 2014
. Retrieved
January 20,
2009
Reid, M. J.; et al. (2009). "Trigonometric parallaxes of massive star-forming regions. VI. Galactic structure, fundamental parameters, and noncircular motions".
The Astrophysical Journal
700
(1):
137–
148.
arXiv
0902.3913
Bibcode
2009ApJ...700..137R
doi
10.1088/0004-637X/700/1/137
S2CID
11347166
Gnedin, O. Y.; et al. (2010). "The mass profile of the Galaxy to 80 kpc".
The Astrophysical Journal
720
(1):
L108–
L112.
arXiv
1005.2619
Bibcode
2010ApJ...720L.108G
doi
10.1088/2041-8205/720/1/L108
S2CID
119245657
Peñarrubia, Jorge; et al. (2014).
"A dynamical model of the local cosmic expansion"
Monthly Notices of the Royal Astronomical Society
433
(3):
2204–
2222.
arXiv
1405.0306
Bibcode
2014MNRAS.443.2204P
doi
10.1093/mnras/stu879
S2CID
119295582
Grand, Robert J J.; Deason, Alis J.; White, Simon D M.; Simpson, Christine M.; Gómez, Facundo A.; Marinacci, Federico; Pakmor, Rüdiger (2019).
"The effects of dynamical substructure on Milky Way mass estimates from the high-velocity tail of the local stellar halo"
Monthly Notices of the Royal Astronomical Society: Letters
487
(1):
L72–
L76.
arXiv
1905.09834
Bibcode
2019MNRAS.487L..72G
doi
10.1093/mnrasl/slz092
S2CID
165163524
McMillan, P. J. (July 2011).
"Mass models of the Milky Way"
Monthly Notices of the Royal Astronomical Society
414
(3):
2446–
2457.
arXiv
1102.4340
Bibcode
2011MNRAS.414.2446M
doi
10.1111/j.1365-2966.2011.18564.x
S2CID
119100616
McMillan, Paul J. (February 11, 2017).
"The mass distribution and gravitational potential of the Milky Way"
Monthly Notices of the Royal Astronomical Society
465
(1):
76–
94.
arXiv
1608.00971
Bibcode
2017MNRAS.465...76M
doi
10.1093/mnras/stw2759
S2CID
119183093
Slobodan Ninković (April 2017).
"Mass Distribution and Gravitational Potential of the Milky Way"
Open Astronomy
26
(1):
1–
6.
Bibcode
2017OAst...26....1N
doi
10.1515/astro-2017-0002
Phelps, Steven; et al. (October 2013). "The Mass of the Milky Way and M31 Using the Method of Least Action".
The Astrophysical Journal
775
(2):
102–
113.
arXiv
1306.4013
Bibcode
2013ApJ...775..102P
doi
10.1088/0004-637X/775/2/102
S2CID
21656852
. 102.
Licquia, Timothy; Newman, J. (2013). "Improved Constraints on the Total Stellar Mass, Color, and Luminosity of the Milky Way".
American Astronomical Society, AAS Meeting #221, #254.11
221
: 254.11.
Bibcode
2013AAS...22125411L
"The Interstellar Medium"
. Archived from
the original
on April 19, 2015
. Retrieved
May 2,
2015
"Lecture Seven: The Milky Way: Gas"
(PDF)
. Archived from
the original
(PDF)
on July 8, 2015
. Retrieved
May 2,
2015
Jiao, Y.-J.; Hammer, F.; Wang, H.-F.; Wang, J.-L.; Amram, P.; Chemin, L.; Yang, Y.-B. (September 27, 2023).
"Detection of the Keplerian decline in the Milky Way rotation curve"
Astronomy & Astrophysics
678
. EDP Sciences: A208.
arXiv
2309.00048
Bibcode
2023A&A...678A.208J
doi
10.1051/0004-6361/202347513
ISSN
0004-6361
McGaugh, Stacy S. (August 1, 2018).
"A Precise Milky Way Rotation Curve Model for an Accurate Galactocentric Distance"
Research Notes of the AAS
(3): 156.
arXiv
1808.09435
Bibcode
2018RNAAS...2..156M
doi
10.3847/2515-5172/aadd4b
ISSN
2515-5172
McClure-Griffiths, N. M.; Dickey, John M. (December 10, 2007).
"Milky Way Kinematics. I. Measurements at the Subcentral Point of the Fourth Quadrant"
The Astrophysical Journal
671
(1):
427–
438.
arXiv
0708.0870
Bibcode
2007ApJ...671..427M
doi
10.1086/522297
ISSN
0004-637X
. Retrieved
January 2,
2026
McClure-Griffiths, N. M.; Dickey, John M. (November 10, 2016).
"MILKY WAY KINEMATICS. II. A UNIFORM INNER GALAXY H i TERMINAL VELOCITY CURVE"
The Astrophysical Journal
831
(2): 124.
arXiv
1608.03683
Bibcode
2016ApJ...831..124M
doi
10.3847/0004-637X/831/2/124
ISSN
0004-637X
Eilers, Anna-Christina; Hogg, David W.; Rix, Hans-Walter; Ness, Melissa K. (January 20, 2019).
"The Circular Velocity Curve of the Milky Way from 5 to 25 kpc"
The Astrophysical Journal
871
(1): 120.
arXiv
1810.09466
Bibcode
2019ApJ...871..120E
doi
10.3847/1538-4357/aaf648
ISSN
0004-637X
McGaugh, Stacy S. (November 1, 2019).
"The Imprint of Spiral Arms on the Galactic Rotation Curve"
The Astrophysical Journal
885
(1): 87.
arXiv
1909.11158
Bibcode
2019ApJ...885...87M
doi
10.3847/1538-4357/ab479b
ISSN
0004-637X
Portail, Matthieu; Gerhard, Ortwin; Wegg, Christopher; Ness, Melissa (February 21, 2017).
"Dynamical modelling of the galactic bulge and bar: the Milky Way's pattern speed, stellar and dark matter mass distribution"
Monthly Notices of the Royal Astronomical Society
465
(2):
1621–
1644.
doi
10.1093/mnras/stw2819
ISSN
0035-8711
Reid, M. J.; Menten, K. M.; Brunthaler, A.; Zheng, X. W.; Dame, T. M.; Xu, Y.; Li, J.; Sakai, N.; Wu, Y.; Immer, K.; Zhang, B.; Sanna, A.; Moscadelli, L.; Rygl, K. L. J.; Bartkiewicz, A.; Hu, B.; Quiroga-Nuñez, L. H.; van Langevelde, H. J. (November 10, 2019).
"Trigonometric Parallaxes of High-mass Star-forming Regions: Our View of the Milky Way"
The Astrophysical Journal
885
(2): 131.
arXiv
1910.03357
Bibcode
2019ApJ...885..131R
doi
10.3847/1538-4357/ab4a11
ISSN
0004-637X
Bird, Sarah A; Xue, Xiang-Xiang; Liu, Chao; Flynn, Chris; Shen, Juntai; Wang, Jie; Yang, Chengqun; Zhai, Meng; Zhu, Ling; Zhao, Gang; Tian, Hai-Jun (August 29, 2022).
"Milky Way mass with K giants and BHB stars using LAMOST, SDSS/SEGUE, and Gaia : 3D spherical Jeans equation and tracer mass estimator"
Monthly Notices of the Royal Astronomical Society
516
(1):
731–
748.
doi
10.1093/mnras/stac2036
ISSN
0035-8711
. Retrieved
January 2,
2026
Wang, WenTing; Han, JiaXin; Cautun, Marius; Li, ZhaoZhou; Ishigaki, Miho N. (2020).
"The mass of our Milky Way"
Science China Physics, Mechanics & Astronomy
63
(10) 109801.
arXiv
1912.02599
Bibcode
2020SCPMA..6309801W
doi
10.1007/s11433-019-1541-6
ISSN
1674-7348
. Retrieved
January 2,
2026
Watkins, Laura L.; van der Marel, Roeland P.; Sohn, Sangmo Tony; Wyn Evans, N. (March 12, 2019).
"Evidence for an Intermediate-mass Milky Way from Gaia DR2 Halo Globular Cluster Motions"
The Astrophysical Journal
873
(2): 118.
arXiv
1804.11348
Bibcode
2019ApJ...873..118W
doi
10.3847/1538-4357/ab089f
ISSN
1538-4357
Camarillo, Tia; Dredger, Pauline; Ratra, Bharat (May 4, 2018). "Median Statistics Estimate of the Galactic Rotational Velocity".
Astrophysics and Space Science
363
(12): 268.
arXiv
1805.01917
Bibcode
2018Ap&SS.363..268C
doi
10.1007/s10509-018-3486-8
S2CID
55697732
Koupelis, Theo; Kuhn, Karl F. (2007).
In Quest of the Universe
. Jones & Bartlett Publishers. p.
492
, Fig. 16–13.
ISBN
978-0-7637-4387-1
Peter Schneider (2006).
Extragalactic Astronomy and Cosmology
. Springer. p. 413.
ISBN
978-3-540-33174-2
Archived
from the original on March 26, 2023
. Retrieved
October 27,
2020
"Ned Wright's Cosmology Tutorial pt. 1"
www.astro.ucla.edu
. July 21, 2017
. Retrieved
May 19,
2025
"The Velocity of Our Galaxy: the End of a 40-Year Mystery"
CEA/The Knowledge Factory
. January 31, 2017.
Archived
from the original on June 2, 2022
. Retrieved
May 5,
2022
"The Milky Way is being pushed through space by a void called the Dipole Repeller"
Wired UK
Archived
from the original on January 6, 2019
. Retrieved
May 5,
2022
Kocevski, D. D.; Ebeling, H. (2006). "On the origin of the Local Group's peculiar velocity".
The Astrophysical Journal
645
(2):
1043–
1053.
arXiv
astro-ph/0510106
Bibcode
2006ApJ...645.1043K
doi
10.1086/503666
S2CID
2760455
Peirani, S; Defreitaspacheco, J (2006). "Mass determination of groups of galaxies: Effects of the cosmological constant".
New Astronomy
11
(4):
325–
330.
arXiv
astro-ph/0508614
Bibcode
2006NewA...11..325P
doi
10.1016/j.newast.2005.08.008
S2CID
685068
Villard, Ray (January 11, 2012).
"The Milky Way Contains at Least 100 Billion Planets According to Survey"
. HubbleSite.org. Archived from
the original
on July 23, 2014
. Retrieved
January 11,
2012
Young, Kelly (June 6, 2006).
"Andromeda Galaxy hosts a trillion stars"
New Scientist
Archived
from the original on January 5, 2011
. Retrieved
June 8,
2006
"Black Holes | Science Mission Directorate"
NASA
Archived
from the original on November 17, 2017
. Retrieved
April 5,
2018
Oka, Tomoharu; Tsujimoto, Shiho; Iwata, Yuhei; Nomura, Mariko; Takekawa, Shunya (October 2017).
"Millimetre-wave emission from an intermediate-mass black hole candidate in the Milky Way"
Nature Astronomy
(10):
709–
712.
arXiv
1707.07603
Bibcode
2017NatAs...1..709O
doi
10.1038/s41550-017-0224-z
ISSN
2397-3366
S2CID
119400213
Archived
from the original on April 24, 2022
. Retrieved
April 24,
2022
Napiwotzki, R. (2009). The galactic population of white dwarfs. In Journal of Physics: Conference Series (Vol. 172, No. 1, p. 012004). IOP Publishing.
"NASA – Neutron Stars"
NASA
Archived
from the original on September 8, 2018
. Retrieved
April 5,
2018
Levine, E. S.; Blitz, L.; Heiles, C. (2006). "The spiral structure of the outer Milky Way in hydrogen".
Science
312
(5781):
1773–
1777.
arXiv
astro-ph/0605728
Bibcode
2006Sci...312.1773L
doi
10.1126/science.1128455
PMID
16741076
S2CID
12763199
Dickey, J. M.; Lockman, F. J. (1990). "H I in the Galaxy".
Annual Review of Astronomy and Astrophysics
28
215–
259.
Bibcode
1990ARA&A..28..215D
doi
10.1146/annurev.aa.28.090190.001243
Savage, B. D.; Wakker, B. P. (2009). "The extension of the transition temperature plasma into the lower galactic halo".
The Astrophysical Journal
702
(2):
1472–
1489.
arXiv
0907.4955
Bibcode
2009ApJ...702.1472S
doi
10.1088/0004-637X/702/2/1472
S2CID
119245570
Connors, Tim W.; Kawata, Daisuke; Gibson, Brad K. (2006).
"N-body simulations of the Magellanic stream"
Monthly Notices of the Royal Astronomical Society
371
(1):
108–
120.
arXiv
astro-ph/0508390
Bibcode
2006MNRAS.371..108C
doi
10.1111/j.1365-2966.2006.10659.x
S2CID
15563258
Coffey, Jerry (May 11, 2017).
"Absolute Magnitude"
. Archived from
the original
on September 13, 2011.
Karachentsev, Igor D.; Karachentseva, Valentina E.; Huchtmeier, Walter K.; Makarov, Dmitry I. (2003).
"A Catalog of Neighboring Galaxies"
The Astronomical Journal
127
(4):
2031–
2068.
Bibcode
2004AJ....127.2031K
doi
10.1086/382905
Borenstein, Seth (February 19, 2011).
"Cosmic census finds crowd of planets in our galaxy"
The Washington Post
Associated Press
{{
cite news
}}
: CS1 maint: deprecated archival service (
link
Sumi, T.; et al. (2011). "Unbound or distant planetary mass population detected by gravitational microlensing".
Nature
473
(7347):
349–
352.
arXiv
1105.3544
Bibcode
2011Natur.473..349S
doi
10.1038/nature10092
PMID
21593867
S2CID
4422627
"Free-Floating Planets May be More Common Than Stars"
. Pasadena, CA: NASA's Jet Propulsion Laboratory. February 18, 2011. Archived from
the original
on May 22, 2011.
The team estimates there are about twice as many of them as stars.
"17 Billion Earth-Size Alien Planets Inhabit Milky Way"
Space.com
. January 7, 2013. Archived from
the original
on October 6, 2014
. Retrieved
January 8,
2013
Overbye, Dennis (November 4, 2013).
"Far-Off Planets Like the Earth Dot the Galaxy"
The New York Times
Archived
from the original on November 5, 2013
. Retrieved
November 5,
2013
Petigura, Eric A.; Howard, Andrew W.; Marcy, Geoffrey W. (October 31, 2013).
"Prevalence of Earth-size planets orbiting Sun-like stars"
Proceedings of the National Academy of Sciences of the United States of America
110
(48):
19273–
19278.
arXiv
1311.6806
Bibcode
2013PNAS..11019273P
doi
10.1073/pnas.1319909110
PMC
3845182
PMID
24191033
Borenstein, Seth (November 4, 2013).
"Milky Way Teeming With Billions Of Earth-Size Planets"
The Associated Press
. The Huffington Post.
Archived
from the original on November 4, 2014.
Khan, Amina (November 4, 2013).
"Milky Way may host billions of Earth-size planets"
Los Angeles Times
Archived
from the original on November 6, 2013
. Retrieved
November 5,
2013
Anglada-Escudé, Guillem; Amado, Pedro J.; Barnes, John; et al. (2016).
"A terrestrial planet candidate in a temperate orbit around Proxima Centauri"
Nature
536
(7617):
437–
440.
arXiv
1609.03449
Bibcode
2016Natur.536..437A
doi
10.1038/nature19106
PMID
27558064
S2CID
4451513
Archived
from the original on October 3, 2021
. Retrieved
September 11,
2021
'Exocomets' Common Across Milky Way Galaxy"
Space.com
. January 7, 2013. Archived from
the original
on September 16, 2014
. Retrieved
January 8,
2013
Overbye, Dennis (November 5, 2020).
"Looking for Another Earth? Here Are 300 Million, Maybe – A new analysis of data from NASA's Kepler spacecraft increases the number of habitable exoplanets thought to exist in this galaxy"
The New York Times
Archived
from the original on November 5, 2020
. Retrieved
November 5,
2020
Fang, Ke; Gallagher, John S.; Halzen, Francis (February 2024).
"The Milky Way revealed to be a neutrino desert by the IceCube Galactic plane observation"
Nature Astronomy
(2):
241–
246.
arXiv
2306.17275
Bibcode
2024NatAs...8..241F
doi
10.1038/s41550-023-02128-0
ISSN
2397-3366
"The Milky Way is warped"
phys.org
Archived
from the original on February 7, 2019
. Retrieved
February 22,
2019
Chen, Xiaodian; Wang, Shu; Deng, Licai; de Grijs, Richard; Liu, Chao; Tian, Hao (February 4, 2019). "An intuitive 3D map of the Galactic warp's precession traced by classical Cepheids".
Nature Astronomy
(4):
320–
325.
arXiv
1902.00998
Bibcode
2019NatAs...3..320C
doi
10.1038/s41550-018-0686-7
ISSN
2397-3366
S2CID
119290364
Gerard de Vaucouleurs (1964),
Interpretation of velocity distribution of the inner regions of the Galaxy
Archived
February 3, 2019, at the
Wayback Machine
Peters, W.L. III. (1975),
Models for the inner regions of the Galaxy. I
Archived
February 3, 2019, at the
Wayback Machine
Hammersley, P. L.; Garzon, F.; Mahoney, T.; Calbet, X. (1994),
Infrared Signatures of the Inner Spiral Arms and Bar
Archived
February 3, 2019, at the
Wayback Machine
McKee, Maggie (August 16, 2005).
"Bar at Milky Way's heart revealed"
New Scientist
. Archived from
the original
on October 9, 2014
. Retrieved
June 17,
2009
Chou, Felicia; Anderson, Janet; Watzke, Megan (January 5, 2015).
"Release 15-001 – NASA's Chandra Detects Record-Breaking Outburst from Milky Way's Black Hole"
NASA
Archived
from the original on January 6, 2015
. Retrieved
January 6,
2015
Gillessen, S.; et al. (2009). "Monitoring stellar orbits around the massive black hole in the Galactic Center".
Astrophysical Journal
692
(2):
1075–
1109.
arXiv
0810.4674
Bibcode
2009ApJ...692.1075G
doi
10.1088/0004-637X/692/2/1075
S2CID
1431308
Reid, M. J.; et al. (November 2009). "A trigonometric parallax of Sgr B2".
The Astrophysical Journal
705
(2):
1548–
1553.
arXiv
0908.3637
Bibcode
2009ApJ...705.1548R
doi
10.1088/0004-637X/705/2/1548
S2CID
1916267
Vanhollebeke, E.; Groenewegen, M. A. T.; Girardi, L. (April 2009). "Stellar populations in the Galactic bulge. Modelling the Galactic bulge with TRILEGAL".
Astronomy and Astrophysics
498
(1):
95–
107.
arXiv
0903.0946
Bibcode
2009A&A...498...95V
doi
10.1051/0004-6361/20078472
S2CID
125177722
Majaess, D. (March 2010). "Concerning the Distance to the Center of the Milky Way and Its Structure".
Acta Astronomica
60
(1): 55.
arXiv
1002.2743
Bibcode
2010AcA....60...55M
Grant, J.; Lin, B. (2000).
"The Stars of the Milky Way"
. Fairfax Public Access Corporation.
Archived
from the original on June 11, 2007
. Retrieved
May 9,
2007
Shen, J.; Rich, R. M.; Kormendy, J.; Howard, C. D.; De Propris, R.; Kunder, A. (2010). "Our Milky Way As a Pure-Disk Galaxy – A Challenge for Galaxy Formation".
The Astrophysical Journal
720
(1):
L72–
L76.
arXiv
1005.0385
Bibcode
2010ApJ...720L..72S
doi
10.1088/2041-8205/720/1/L72
S2CID
118470423
Ciambur, Bogdan C.; Graham, Alister W.; Bland-Hawthorn, Joss (2017).
"Quantifying the (X/peanut)-shaped structure of the Milky Way – new constraints on the bar geometry"
Monthly Notices of the Royal Astronomical Society
471
(4): 3988.
arXiv
1706.09902
Bibcode
2017MNRAS.471.3988C
doi
10.1093/mnras/stx1823
S2CID
119376558
Jones, Mark H.; Lambourne, Robert J.; Adams, David John (2004).
An Introduction to Galaxies and Cosmology
. Cambridge University Press. pp.
50–
51.
ISBN
978-0-521-54623-2
Archived
from the original on March 26, 2023
. Retrieved
August 23,
2020
Ghez, A. M.; et al. (December 2008). "Measuring distance and properties of the Milky Way's central supermassive black hole with stellar orbits".
The Astrophysical Journal
689
(2):
1044–
1062.
arXiv
0808.2870
Bibcode
2008ApJ...689.1044G
doi
10.1086/592738
S2CID
18335611
Wang, Q.D.; Nowak, M.A.; Markoff, S.B.; Baganoff, F.K.; Nayakshin, S.; Yuan, F.; Cuadra, J.; Davis, J.; Dexter, J.; Fabian, A.C.; Grosso, N.; Haggard, D.; Houck, J.; Ji, L.; Li, Z.; Neilsen, J.; Porquet, D.; Ripple, F.; Shcherbakov, R.V. (2013). "Dissecting X-ray-Emitting Gas Around the Center of Our Galaxy".
Science
341
(6149):
981–
983.
arXiv
1307.5845
Bibcode
2013Sci...341..981W
doi
10.1126/science.1240755
PMID
23990554
S2CID
206550019
Blandford, R. D. (August 8–12, 1998).
Origin and Evolution of Massive Black Holes in Galactic Nuclei
. Galaxy Dynamics, proceedings of a conference held at Rutgers University, ASP Conference Series. Vol. 182. Rutgers University (published August 1999).
arXiv
astro-ph/9906025
Bibcode
1999ASPC..182...87B
Frolov, Valeri P.; Zelnikov, Andrei (2011).
Introduction to Black Hole Physics
. Oxford University Press. pp. 11, 36.
ISBN
978-0-19-969229-3
Archived
from the original on August 10, 2016.
Cabrera-Lavers, A.; et al. (December 2008). "The long Galactic bar as seen by UKIDSS Galactic plane survey".
Astronomy and Astrophysics
491
(3):
781–
787.
arXiv
0809.3174
Bibcode
2008A&A...491..781C
doi
10.1051/0004-6361:200810720
S2CID
15040792
Nishiyama, S.; et al. (2005). "A distinct structure inside the Galactic bar".
The Astrophysical Journal
621
(2): L105.
arXiv
astro-ph/0502058
Bibcode
2005ApJ...621L.105N
doi
10.1086/429291
S2CID
399710
Alcock, C.; et al. (1998).
"The RR Lyrae population of the Galactic Bulge from the MACHO database: mean colors and magnitudes"
The Astrophysical Journal
492
(2):
190–
199.
Bibcode
1998ApJ...492..190A
doi
10.1086/305017
Kunder, A.; Chaboyer, B. (2008). "Metallicity analysis of Macho Galactic Bulge RR0 Lyrae stars from their light curves".
The Astronomical Journal
136
(6):
2441–
2452.
arXiv
0809.1645
Bibcode
2008AJ....136.2441K
doi
10.1088/0004-6256/136/6/2441
S2CID
16046532
"Introduction: Galactic Ring Survey"
. Boston University. September 12, 2005.
Archived
from the original on July 13, 2007
. Retrieved
May 10,
2007
Bhat, C. L.; Kifune, T.; Wolfendale, A. W. (November 21, 1985). "A cosmic-ray explanation of the galactic ridge of cosmic X-rays".
Nature
318
(6043):
267–
269.
Bibcode
1985Natur.318..267B
doi
10.1038/318267a0
S2CID
4262045
Wright, Katherine (2023).
"Milky Way Viewed through Neutrinos"
Physics
16
115. Physics 16, 115 (June 29, 2023).
Bibcode
2023PhyOJ..16..115W
doi
10.1103/Physics.16.115
Kurahashi Neilson first came up with the idea to use cascade neutrinos to map the Milky Way in 2015.
Chang, Kenneth (June 29, 2023).
"Neutrinos Build a Ghostly Map of the Milky Way – Astronomers for the first time detected neutrinos that originated within our local galaxy using a new technique"
The New York Times
. Retrieved
June 30,
2023
{{
cite news
}}
: CS1 maint: deprecated archival service (
link
IceCube Collaboration (June 29, 2023).
"Observation of high-energy neutrinos from the Galactic plane"
Science
380
(6652):
1338–
1343.
arXiv
2307.04427
Bibcode
2023Sci...380.1338I
doi
10.1126/science.adc9818
hdl
2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/360407
PMID
37384687
S2CID
259287623
. Retrieved
June 30,
2023
{{
cite journal
}}
: CS1 maint: deprecated archival service (
link
Georg Weidenspointner; et al. (January 10, 2008). "An asymmetric distribution of positrons in the Galactic disk revealed by γ-rays".
Nature
451
(7175):
159–
162.
Bibcode
2008Natur.451..159W
doi
10.1038/nature06490
PMID
18185581
S2CID
4333175
Naeye, Bob (January 9, 2008).
"Satellite Explains Giant Cloud of Antimatter"
NASA
Archived
from the original on May 6, 2021
. Retrieved
July 2,
2021
"Antimatter Clouds and Fountains – NASA Press Release 97-83"
HEASARC
. April 28, 1997.
Archived
from the original on July 9, 2021
. Retrieved
July 2,
2021
Overbye, Dennis (November 9, 2010).
"Bubbles of Energy Are Found in Galaxy"
The New York Times
Archived
from the original on January 10, 2016.
"NASA's Fermi Telescope Finds Giant Structure in our Galaxyl"
NASA
. Archived from
the original
on August 23, 2014
. Retrieved
November 10,
2010
Carretti, E.; Crocker, R. M.; Staveley-Smith, L.; Haverkorn, M.; Purcell, C.; Gaensler, B. M.; Bernardi, G.; Kesteven, M. J.; Poppi, S. (2013). "Giant magnetized outflows from the centre of the Milky Way".
Nature
493
(7430):
66–
69.
arXiv
1301.0512
Bibcode
2013Natur.493...66C
doi
10.1038/nature11734
PMID
23282363
S2CID
4426371
Churchwell, E.; et al. (2009). "The Spitzer/GLIMPSE surveys: a new view of the Milky Way".
Publications of the Astronomical Society of the Pacific
121
(877):
213–
230.
Bibcode
2009PASP..121..213C
doi
10.1086/597811
S2CID
15529740
Taylor, J. H.; Cordes, J. M. (1993).
"Pulsar distances and the galactic distribution of free electrons"
The Astrophysical Journal
411
: 674.
Bibcode
1993ApJ...411..674T
doi
10.1086/172870
Russeil, D. (2003).
"Star-forming complexes and the spiral structure of our Galaxy"
Astronomy and Astrophysics
397
133–
146.
Bibcode
2003A&A...397..133R
doi
10.1051/0004-6361:20021504
Dame, T. M.; Hartmann, D.; Thaddeus, P. (2001). "The Milky Way in molecular clouds: A new complete CO survey".
The Astrophysical Journal
547
(2):
792–
813.
arXiv
astro-ph/0009217
Bibcode
2001ApJ...547..792D
doi
10.1086/318388
S2CID
118888462
Benjamin, R. A. (2008). Beuther, H.; Linz, H.; Henning, T. (eds.).
The Spiral Structure of the Galaxy: Something Old, Something New..
Massive Star Formation: Observations Confront Theory
. Vol. 387. Astronomical Society of the Pacific Conference Series. p. 375.
Bibcode
2008ASPC..387..375B
See also
Bryner, Jeanna (June 3, 2008).
"New Images: Milky Way Loses Two Arms"
Space.com
Archived
from the original on June 4, 2008
. Retrieved
June 4,
2008
Majaess, D. J.; Turner, D. G.; Lane, D. J. (2009). "Searching Beyond the Obscuring Dust Between the Cygnus-Aquila Rifts for Cepheid Tracers of the Galaxy's Spiral Arms".
The Journal of the American Association of Variable Star Observers
37
(2): 179.
arXiv
0909.0897
Bibcode
2009JAVSO..37..179M
Lépine, J. R. D.; et al. (2011).
"The spiral structure of the Galaxy revealed by CS sources and evidence for the 4:1 resonance"
Monthly Notices of the Royal Astronomical Society
414
(2):
1607–
1616.
arXiv
1010.1790
Bibcode
2011MNRAS.414.1607L
doi
10.1111/j.1365-2966.2011.18492.x
S2CID
118477787
Drimmel, R. (2000). "Evidence for a two-armed spiral in the Milky Way".
Astronomy & Astrophysics
358
L13–
L16.
arXiv
astro-ph/0005241
Bibcode
2000A&A...358L..13D
Sanna, A.; Reid, M. J.; Dame, T. M.; Menten, K. M.; Brunthaler, A. (2017). "Mapping spiral structure on the far side of the Milky Way".
Science
358
(6360):
227–
230.
arXiv
1710.06489
Bibcode
2017Sci...358..227S
doi
10.1126/science.aan5452
PMID
29026043
S2CID
206660521
McClure-Griffiths, N. M.; Dickey, J. M.; Gaensler, B. M.; Green, A. J. (2004). "A Distant Extended Spiral Arm in the Fourth Quadrant of the Milky Way".
The Astrophysical Journal
607
(2): L127.
arXiv
astro-ph/0404448
Bibcode
2004ApJ...607L.127M
doi
10.1086/422031
S2CID
119327129
Benjamin, R. A.; et al. (2005). "First GLIMPSE results on the stellar structure of the Galaxy".
The Astrophysical Journal
630
(2):
L149–
L152.
arXiv
astro-ph/0508325
Bibcode
2005ApJ...630L.149B
doi
10.1086/491785
S2CID
14782284
"Massive stars mark out Milky Way's 'missing' arms"
(Press release). Leeds, UK: University of Leeds. December 17, 2013. Archived from
the original
on December 18, 2013
. Retrieved
December 18,
2013
Westerholm, Russell (December 18, 2013).
"Milky Way Galaxy has four arms, reaffirming old data and contradicting recent research"
University Herald
Archived
from the original on December 19, 2013
. Retrieved
December 18,
2013
Urquhart, J. S.; Figura, C. C.; Moore, T. J. T.; Hoare, M. G.; et al. (January 2014).
"The RMS Survey: Galactic distribution of massive star formation"
Monthly Notices of the Royal Astronomical Society
437
(2):
1791–
1807.
arXiv
1310.4758
Bibcode
2014MNRAS.437.1791U
doi
10.1093/mnras/stt2006
S2CID
14266458
van Woerden, H.; et al. (1957). "Expansion d'une structure spirale dans le noyau du Système Galactique, et position de la radiosource Sagittarius A".
Comptes Rendus de l'Académie des Sciences
(in French).
244
1691–
1695.
Bibcode
1957CRAS..244.1691V
Dame, T. M.; Thaddeus, P. (2008). "A New Spiral Arm of the Galaxy: The Far 3-Kpc Arm".
The Astrophysical Journal
683
(2):
L143–
L146.
arXiv
0807.1752
Bibcode
2008ApJ...683L.143D
doi
10.1086/591669
S2CID
7450090
"Milky Way's Inner Beauty Revealed"
. Center for Astrophysics | Harvard & Smithsonian. June 3, 2008.
Archived
from the original on July 5, 2013
. Retrieved
July 7,
2015
Matson, John (September 14, 2011).
"Star-Crossed: Milky Way's Spiral Shape May Result from a Smaller Galaxy's Impact"
Scientific American
Archived
from the original on December 3, 2013
. Retrieved
July 7,
2015
Mel'Nik, A.; Rautiainen, A. (2005).
"Kinematics of the outer pseudorings and the spiral structure of the Galaxy"
(PDF)
Astronomy Letters
35
(9):
609–
624.
arXiv
0902.3353
Bibcode
2009AstL...35..609M
CiteSeerX
10.1.1.247.4658
doi
10.1134/s1063773709090047
S2CID
15989486
. Archived from
the original
(PDF)
on March 31, 2011.
Mel'Nik, A. (2006). "Outer pseudoring in the galaxy".
Astronomische Nachrichten
326
(7):
589–
605.
arXiv
astro-ph/0510569
Bibcode
2005AN....326Q.599M
doi
10.1002/asna.200585006
S2CID
117118657
Lopez-Corredoira, M.; et al. (July 2012). "Comments on the "Monoceros" affair".
arXiv
1207.2749
astro-ph.GA
].
Byrd, Deborah
(February 5, 2019).
"The Milky Way is warped"
EarthSky
Archived
from the original on February 6, 2019
. Retrieved
February 6,
2019
Harris, William E. (February 2003).
"Catalog of Parameters for Milky Way Globular Clusters: The Database"
(text)
. SEDS.
Archived
from the original on March 9, 2012
. Retrieved
May 10,
2007
Dauphole, B.; et al. (September 1996). "The kinematics of globular clusters, apocentric distances and a halo metallicity gradient".
Astronomy and Astrophysics
313
119–
128.
Bibcode
1996A&A...313..119D
Gnedin, O. Y.; Lee, H. M.; Ostriker, J. P. (1999). "Effects of Tidal Shocks on the Evolution of Globular Clusters".
The Astrophysical Journal
522
(2):
935–
949.
arXiv
astro-ph/9806245
Bibcode
1999ApJ...522..935G
doi
10.1086/307659
S2CID
11143134
Janes, K.A.; Phelps, R.L. (1980).
"The galactic system of old star clusters: The development of the galactic disk"
The Astronomical Journal
108
1773–
1785.
Bibcode
1994AJ....108.1773J
doi
10.1086/117192
Ibata, R.; et al. (2005). "On the accretion origin of a vast extended stellar disk around the Andromeda Galaxy".
The Astrophysical Journal
634
(1):
287–
313.
arXiv
astro-ph/0504164
Bibcode
2005ApJ...634..287I
doi
10.1086/491727
S2CID
17803544
"Outer Disk Ring?"
. SolStation. Archived from
the original
on June 2, 2007
. Retrieved
May 10,
2007
T.M. Dame; P. Thaddeus (2011). "A Molecular Spiral Arm in the Far Outer Galaxy".
The Astrophysical Journal
734
(1): L24.
arXiv
1105.2523
Bibcode
2011ApJ...734L..24D
doi
10.1088/2041-8205/734/1/l24
S2CID
118301649
Martin, N. F.; Ibata, R. A.; Bellazzini, M.; Irwin, M. J.; Lewis, G. F.; Dehnen, W. (2004).
"A dwarf galaxy remnant in Canis Major: the fossil of an in-plane accretion on to the Milky Way"
Monthly Notices of the Royal Astronomical Society
348
(1):
12–
23.
arXiv
astro-ph/0311010
Bibcode
2004MNRAS.348...12M
doi
10.1111/j.1365-2966.2004.07331.x
Momany, Y.; Zaggia, S. R.; Bonifacio, P.; Piotto, G.; Angeli, F. De; Bedin, L. R.; Carraro, G. (July 1, 2004).
"Probing the Canis Major stellar over-density as due to the Galactic warp"
Astronomy & Astrophysics
421
(2):
L29–
L32.
arXiv
astro-ph/0405526
Bibcode
2004A&A...421L..29M
doi
10.1051/0004-6361:20040183
hdl
11577/2467288
ISSN
0004-6361
Carballo-Bello, Julio A; Martínez-Delgado, David; Corral-Santana, Jesús M; Alfaro, Emilio J; Navarrete, Camila; Vivas, A Katherina; Catelan, Márcio (December 31, 2020).
"A revised view of the Canis Major stellar overdensity with DECam and Gaia: new evidence of a stellar warp of blue stars"
Monthly Notices of the Royal Astronomical Society
501
(2):
1690–
1700.
arXiv
2009.01855
doi
10.1093/mnras/staa2655
ISSN
0035-8711
Jurić, M.; et al. (February 2008). "The Milky Way Tomography with SDSS. I. Stellar Number Density Distribution".
The Astrophysical Journal
673
(2):
864–
914.
arXiv
astro-ph/0510520
Bibcode
2008ApJ...673..864J
doi
10.1086/523619
S2CID
11935446
Boen, Brooke.
"NASA's Chandra Shows Milky Way is Surrounded by Halo of Hot Gas"
. Brooke Boen.
Archived
from the original on October 23, 2012
. Retrieved
October 28,
2012
Gupta, A.; Mathur, S.; Krongold, Y.; Nicastro, F.; Galeazzi, M. (2012). "A Huge Reservoir of Ionized Gas Around the Milky Way: Accounting for the Missing Mass?".
The Astrophysical Journal
756
(1): L8.
arXiv
1205.5037
Bibcode
2012ApJ...756L...8G
doi
10.1088/2041-8205/756/1/L8
S2CID
118567708
"Galactic Halo: Milky Way is Surrounded by Huge Halo of Hot Gas"
Smithsonian Astrophysical Observatory
. September 24, 2012.
Archived
from the original on October 29, 2012.
Communications, Discovery.
"Our Galaxy Swims Inside a Giant Pool of Hot Gas"
Discovery News
. Discovery Communications.
Archived
from the original on October 29, 2012
. Retrieved
October 28,
2012
J.D. Harrington; Janet Anderson; Peter Edmonds (September 24, 2012).
"NASA's Chandra Shows Milky Way is Surrounded by Halo of Hot Gas"
NASA
Archived
from the original on October 23, 2012.
"Milky Way's origins are not what they seem"
Phys.org
. July 27, 2017.
Archived
from the original on July 27, 2017
. Retrieved
July 27,
2017
Borah, Debasish; Dutta, Manoranjan; Mahapatra, Satyabrata; Sahu, Narendra (2022). "Boosted self-interacting dark matter and XENON1T excess".
Nuclear Physics B
979
115787.
arXiv
2107.13176
Bibcode
2022NuPhB.97915787B
doi
10.1016/j.nuclphysb.2022.115787
S2CID
236469147
Legassick, Daniel (2015). "The Age Distribution of Potential Intelligent Life in the Milky Way".
arXiv
1509.02832
astro-ph.GA
].
Wethington, Nicholas (May 27, 2009).
"Formation of the Milky Way"
Universe Today
. Archived from
the original
on August 17, 2014.
Buser, R. (2000). "The Formation and Early Evolution of the Milky Way Galaxy".
Science
287
(5450):
69–
74.
Bibcode
2000Sci...287...69B
doi
10.1126/science.287.5450.69
PMID
10615051
Wakker, B. P.; Van Woerden, H. (1997). "High-Velocity Clouds".
Annual Review of Astronomy and Astrophysics
35
217–
266.
Bibcode
1997ARA&A..35..217W
doi
10.1146/annurev.astro.35.1.217
S2CID
117861711
Lockman, F. J.; et al. (2008). "The Smith Cloud: A High-Velocity Cloud Colliding with the Milky Way".
The Astrophysical Journal
679
(1):
L21–
L24.
arXiv
0804.4155
Bibcode
2008ApJ...679L..21L
doi
10.1086/588838
S2CID
118393177
Kruijssen, J M Diederik; Pfeffer, Joel L; Chevance, Mélanie; Bonaca, Ana; Trujillo-Gomez, Sebastian; Bastian, Nate; Reina-Campos, Marta; Crain, Robert A; Hughes, Meghan E (October 2020).
"Kraken reveals itself – the merger history of the Milky Way reconstructed with the E-MOSAICS simulations"
Monthly Notices of the Royal Astronomical Society
498
(2):
2472–
2491.
arXiv
2003.01119
doi
10.1093/mnras/staa2452
Archived
from the original on November 16, 2020
. Retrieved
November 15,
2020
Young, Monica (November 13, 2020).
"Star Clusters reveal the "Kraken" in the Milky Way's Past"
Sky and Telescope
Archived
from the original on November 15, 2020
. Retrieved
November 15,
2020
Yin, J.; Hou, J.L; Prantzos, N.; Boissier, S.; et al. (2009). "Milky Way versus Andromeda: a tale of two disks".
Astronomy and Astrophysics
505
(2):
497–
508.
arXiv
0906.4821
Bibcode
2009A&A...505..497Y
doi
10.1051/0004-6361/200912316
S2CID
14344453
Hammer, F.; Puech, M.; Chemin, L.; Flores, H.; et al. (2007). "The Milky Way, an Exceptionally Quiet Galaxy: Implications for the Formation of Spiral Galaxies".
The Astrophysical Journal
662
(1):
322–
334.
arXiv
astro-ph/0702585
Bibcode
2007ApJ...662..322H
doi
10.1086/516727
S2CID
18002823
Mutch, S.J.; Croton, D.J.; Poole, G.B. (2011). "The Mid-life Crisis of the Milky Way and M31".
The Astrophysical Journal
736
(2): 84.
arXiv
1105.2564
Bibcode
2011ApJ...736...84M
doi
10.1088/0004-637X/736/2/84
S2CID
119280671
Licquia, T.; Newman, J.A.; Poole, G.B. (2012). "What Is The Color Of The Milky Way?".
American Astronomical Society
219
: 252.08.
Bibcode
2012AAS...21925208L
"A firestorm of star birth (artist's illustration)"
www.spacetelescope.org
. ESA/Hubble.
Archived
from the original on April 13, 2015
. Retrieved
April 14,
2015
Cayrel; et al. (2001). "Measurement of stellar age from uranium decay".
Nature
409
(6821):
691–
692.
arXiv
astro-ph/0104357
Bibcode
2001Natur.409..691C
doi
10.1038/35055507
PMID
11217852
S2CID
17251766
Cowan, J. J.; Sneden, C.; Burles, S.; Ivans, I. I.; Beers, T. C.; Truran, J. W.; Lawler, J. E.;
Primas, F.
; Fuller, G. M.; et al. (2002). "The Chemical Composition and Age of the Metal-poor Halo Star BD +17o3248".
The Astrophysical Journal
572
(2):
861–
879.
arXiv
astro-ph/0202429
Bibcode
2002ApJ...572..861C
doi
10.1086/340347
S2CID
119503888
Krauss, L. M.; Chaboyer, B. (2003). "Age Estimates of Globular Clusters in the Milky Way: Constraints on Cosmology".
Science
299
(5603):
65–
69.
Bibcode
2003Sci...299...65K
doi
10.1126/science.1075631
PMID
12511641
S2CID
10814581
Johns Hopkins University
(November 5, 2018).
"Johns Hopkins scientist finds elusive star with origins close to Big Bang"
EurekAlert!
Archived
from the original on November 6, 2018
. Retrieved
November 5,
2018
Rosen, Jill (November 5, 2018).
"Johns Hopkins scientist finds elusive star with origins close to Big Bang – The newly discovered star's composition indicates that, in a cosmic family tree, it could be as little as one generation removed from the Big Bang"
Johns Hopkins University
Archived
from the original on November 6, 2018
. Retrieved
November 5,
2018
Schlaufman, Kevin C.; Thompson, Ian B.; Casey, Andrew R. (November 5, 2018).
"An Ultra Metal-poor Star Near the Hydrogen-burning Limit"
The Astrophysical Journal
867
(2): 98.
arXiv
1811.00549
Bibcode
2018ApJ...867...98S
doi
10.3847/1538-4357/aadd97
S2CID
54511945
Frebel, A.; et al. (2007). "Discovery of HE 1523-0901, a strongly
-process-enhanced metal-poor star with detected uranium".
The Astrophysical Journal
660
(2): L117.
arXiv
astro-ph/0703414
Bibcode
2007ApJ...660L.117F
doi
10.1086/518122
S2CID
17533424
Creevey, O. L.; Thévenin, F.; Berio, P.; Heiter, U.; von Braun, K.; Mourard, D.; Bigot, L.; Boyajian, T.S.; Kervella, P.; Morel, P.; Pichon, B.; Chiavassa, A.; Nardetto, N.; Perraut, K.; Meilland, A.; Mc Alister, H. A.; Ten Brummelaar, T.A.; Farrington, C.; Sturmann, J.; Sturmann, L.; Turner, N. (2015). "Benchmark stars for Gaia Fundamental properties of the Population II star HD 140283 from interferometric, spectroscopic, and photometric data".
Astronomy and Astrophysics
575
: A26.
arXiv
1410.4780
Bibcode
2015A&A...575A..26C
doi
10.1051/0004-6361/201424310
S2CID
18003446
Jiangling Tang; Meredith Joyce (2021).
"Revised Best Estimates for the Age and Mass of the Methuselah Star HD 140283 Using MESA and Interferometry and Implications for 1D Convection"
Research Notes of the AAS
(5): 117.
arXiv
2105.11311
Bibcode
2021RNAAS...5..117T
doi
10.3847/2515-5172/ac01ca
S2CID
235166094
. 117.
Specktor, Brandon (March 23, 2019).
"Astronomers Find Fossils of Early Universe Stuffed in Milky Way's Bulge"
Live Science
Archived
from the original on March 23, 2019
. Retrieved
March 24,
2019
del Peloso, E. F. (2005). "The age of the Galactic thin disk from Th/Eu nucleocosmochronology. III. Extended sample".
Astronomy and Astrophysics
440
(3):
1153–
1159.
arXiv
astro-ph/0506458
Bibcode
2005A&A...440.1153D
doi
10.1051/0004-6361:20053307
S2CID
16484977
Skibba, Ramon (2016), "Milky Way retired early from star making" (New Scientist, March 5, 2016), p.9
Lynden-Bell, D. (March 1, 1976).
"Dwarf Galaxies and Globular Clusters in High Velocity Hydrogen Streams"
Monthly Notices of the Royal Astronomical Society
174
(3):
695–
710.
Bibcode
1976MNRAS.174..695L
doi
10.1093/mnras/174.3.695
ISSN
0035-8711
Kroupa, P.; Theis, C.; Boily, C. M. (2005).
"The great disk of Milky-Way satellites and cosmological sub-structures"
Astronomy and Astrophysics
431
(2):
517–
521.
arXiv
astro-ph/0410421
Bibcode
2005A&A...431..517K
doi
10.1051/0004-6361:20041122
Tully, R. Brent; Shaya, Edward J.; Karachentsev, Igor D.;
Courtois, Hélène M.
; Kocevski, Dale D.; Rizzi, Luca; Peel, Alan (March 2008). "Our Peculiar Motion Away from the Local Void".
The Astrophysical Journal
676
(1):
184–
205.
arXiv
0705.4139
Bibcode
2008ApJ...676..184T
doi
10.1086/527428
S2CID
14738309
Hadhazy, Adam (November 3, 2016).
"Why Nothing Really Matters"
Discover Magazine
Archived
from the original on April 24, 2022
. Retrieved
April 24,
2022
R. Brent Tully; Helene Courtois; Yehuda Hoffman; Daniel Pomarède (September 2, 2014). "The Laniakea supercluster of galaxies".
Nature
513
(7516) (published September 4, 2014):
71–
73.
arXiv
1409.0880
Bibcode
2014Natur.513...71T
doi
10.1038/nature13674
PMID
25186900
S2CID
205240232
De Vaucouleurs, Gerard; De Vaucouleurs, Antoinette; Corwin, Herold G.; Buta, Ronald J.; Paturel, Georges; Fouque, Pascal (1991).
Third Reference Catalogue of Bright Galaxies
Bibcode
1991rc3..book.....D
doi
10.1007/978-1-4757-4363-0
ISBN
978-1-4757-4365-4
Putman, M. E.; Staveley-Smith, L.; Freeman, K. C.; Gibson, B. K.; Barnes, D. G. (2003). "The Magellanic Stream, High-Velocity Clouds, and the Sculptor Group".
The Astrophysical Journal
586
(1):
170–
194.
arXiv
astro-ph/0209127
Bibcode
2003ApJ...586..170P
doi
10.1086/344477
S2CID
6911875
Sergey E. Koposov; Vasily Belokurov; Gabriel Torrealba; N. Wyn Evans (March 10, 2015). "Beasts of the Southern Wild. Discovery of a large number of Ultra Faint satellites in the vicinity of the Magellanic Clouds".
The Astrophysical Journal
805
(2): 130.
arXiv
1503.02079
Bibcode
2015ApJ...805..130K
doi
10.1088/0004-637X/805/2/130
S2CID
118267222
Noyola, E.; Gebhardt, K.; Bergmann, M. (April 2008). "Gemini and Hubble Space Telescope Evidence for an Intermediate-Mass Black Hole in ω Centauri".
The Astrophysical Journal
676
(2):
1008–
1015.
arXiv
0801.2782
Bibcode
2008ApJ...676.1008N
doi
10.1086/529002
S2CID
208867075
Kroupa, P.; Theis, C.; Boily, C.M. (February 2005). "The great disk of Milky-Way satellites and cosmological sub-structures".
Astronomy and Astrophysics
431
(2):
517–
521.
arXiv
astro-ph/0410421
Bibcode
2005A&A...431..517K
doi
10.1051/0004-6361:20041122
S2CID
55827105
Pawlowski, M.; Pflamm-Altenburg, J.; Kroupa, P. (June 2012).
"The VPOS: a vast polar structure of satellite galaxies, globular clusters and streams around the Milky Way"
Monthly Notices of the Royal Astronomical Society
423
(2):
1109–
1126.
arXiv
1204.5176
Bibcode
2012MNRAS.423.1109P
doi
10.1111/j.1365-2966.2012.20937.x
S2CID
55501752
Pawlowski, M.; Famaey, B.; Jerjen, H.; Merritt, D.; Kroupa, P.; Dabringhausen, J.; Lueghausen, F.; Forbes, D.; Hensler, G.; Hammer, F.; Puech, M.; Fouquet, S.; Flores, H.; Yang, Y. (August 2014).
"Co-orbiting satellite galaxy structures are still in conflict with the distribution of primordial dwarf galaxies"
Monthly Notices of the Royal Astronomical Society
423
(3):
2362–
2380.
arXiv
1406.1799
Bibcode
2014MNRAS.442.2362P
doi
10.1093/mnras/stu1005
"Milky Way Galaxy is warped and vibrating like a drum"
(Press release).
University of California, Berkeley
. January 9, 2006. Archived from
the original
on July 16, 2014
. Retrieved
October 18,
2007
Wong, Janet (April 14, 2000).
"Astrophysicist maps out our own galaxy's end"
. University of Toronto. Archived from
the original
on January 8, 2007
. Retrieved
January 11,
2007
Junko Ueda; et al. (2014). "Cold molecular gas in merger remnants. I. Formation of molecular gas disks".
The Astrophysical Journal Supplement Series
214
(1): 1.
arXiv
1407.6873
Bibcode
2014ApJS..214....1U
doi
10.1088/0067-0049/214/1/1
S2CID
716993
Schiavi, Riccardo; Capuzzo-Dolcetta, Roberto; Arca-Sedda, Manuel; Spera, Mario (October 2020). "Future merger of the Milky Way with the Andromeda galaxy and the fate of their supermassive black holes".
Astronomy & Astrophysics
642
: A30.
arXiv
2102.10938
Bibcode
2020A&A...642A..30S
doi
10.1051/0004-6361/202038674
S2CID
224991193
Further reading
Dambeck, Thorsten (March 2008). "Gaia's Mission to the Milky Way".
Sky & Telescope
115
(3):
36–
39.
Bibcode
2008S&T...115c..36D
Chiappini, Cristina (November–December 2001).
"The Formation and Evolution of the Milky Way"
(PDF)
American Scientist
89
(6):
506–
515.
doi
10.1511/2001.40.745
McTier, Moiya (August 16, 2022).
The Milky Way
. Grand Central Publishing.
ISBN
978-1-5387-5415-3
Plait, Phil
, "The Milky Way's Secrets: Our galaxy's night-sky spectacle sparked
scientific revolutions
",
Scientific American
, vol. 329, no. 4 (November 2023), pp. 86–87.
Belkora, Leila (2021).
Minding the Heavens:The Story of our Discovery of the Milky Way
. Milton: Taylor & Francis Group.
ISBN
978-0-367-41722-2
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