andromeda galaxy

 

  • [67][11] However, the galaxy has a high inclination as seen from Earth and its interstellar dust absorbs an unknown amount of light, so it is difficult to estimate its actual
    brightness and other authors have given other values for the luminosity of the Andromeda Galaxy (some authors even propose it is the second-brightest galaxy within a radius of 10 megaparsecs of the Milky Way, after the Sombrero Galaxy,[68]
    with an absolute magnitude of around −22.21[e] or close[69]).

  • According to recent studies, the Andromeda Galaxy lies in what in the Galaxy color–magnitude diagram is known as the “green valley”, a region populated by galaxies like the
    Milky Way in transition from the “blue cloud” (galaxies actively forming new stars) to the “red sequence” (galaxies that lack star formation).

  • To support his claim of the Great Andromeda Nebula being, in fact, an external galaxy, Curtis also noted the appearance of dark lanes within Andromeda which resembled the
    dust clouds in our own galaxy, as well as historical observations of Andromeda Galaxy’s significant Doppler shift.

  • His measurement demonstrated conclusively that this feature was not a cluster of stars and gas within our own galaxy, but an entirely separate galaxy located a significant
    distance from the Milky Way.

  • In simulated galaxies with similar properties to the Andromeda Galaxy, star formation is expected to extinguish within about five billion years, even accounting for the expected,
    short-term increase in the rate of star formation due to the collision between the Andromeda Galaxy and the Milky Way.

  • It has been proposed that the observed double nucleus could be explained if P1 is the projection of a disk of stars in an eccentric orbit around the central black hole.

  • [90] Studies of the extended halo of the Andromeda Galaxy show that it is roughly comparable to that of the Milky Way, with stars in the halo being generally “metal-poor”,
    and increasingly so with greater distance.

  • Over the Andromeda Galaxy’s lifetime, nearly half of the heavy elements made by its stars have been ejected far beyond the galaxy’s 200,000-light-year-diameter stellar disk.

  • [70] The rate of star formation in the Milky Way is much higher, with the Andromeda Galaxy producing only about one solar mass per year compared to 3–5 solar masses for the
    Milky Way.

  • [1] However, infrared data from the 2MASS survey and from the Spitzer Space Telescope showed that Andromeda is actually a barred spiral galaxy, like the Milky Way, with Andromeda’s
    bar major axis oriented 55 degrees anti-clockwise from the disc major axis.

  • [88] Later studies with the help of the Spitzer Space Telescope showed how the Andromeda Galaxy’s spiral structure in the infrared appears to be composed of two spiral arms
    that emerge from a central bar and continue beyond the large ring mentioned above.

  • [84] Close examination of the inner region of the Andromeda Galaxy with the same telescope also showed a smaller dust ring that is believed to have been caused by the interaction
    with M32 more than 200 million years ago.

  • [91] The stars in the extended halos of the Andromeda Galaxy and the Milky Way may extend nearly one third the distance separating the two galaxies.

  • This event produced high rates of star formation across the Andromeda Galaxy’s disk—even some globular clusters—and disturbed M33’s outer disk.

  • [22] Another massive globular cluster, named 037-B327 and discovered in 2006 as is heavily reddened by the Andromeda Galaxy’s interstellar dust, was thought to be more massive
    than G1 and the largest cluster of the Local Group;[108] however, other studies have shown it is actually similar in properties to G1.

  • [87] This ring is hidden from visible light images of the galaxy because it is composed primarily of cold dust, and most of the star formation that is taking place in the
    Andromeda Galaxy is concentrated there.

  • [d] Mass estimates Until 2018, mass estimates for the Andromeda Galaxy’s halo (including dark matter) gave a value of approximately 1.5×1012 M☉,[48] compared to 8×1011 M☉
    for the Milky Way.

  • The mass of either galaxy is difficult to estimate with any accuracy, but it was long thought that the Andromeda Galaxy is more massive than the Milky Way by a margin of some
    25% to 50%.

  • )[35] Baade also discovered that there were two types of Cepheid variable stars, which resulted in a doubling of the distance estimate to Andromeda, as well as the remainder
    of the universe.

  • The Andromeda Galaxy (IPA: /ænˈdrɒmɪdə/), also known as Messier 31, M31, or NGC 224 and originally the Andromeda Nebula, is a barred spiral galaxy with diameter of about 46.56
    kiloparsecs (152,000 light-years)[8] approximately 2.5 million light-years (770 kiloparsecs) from Earth and the nearest large galaxy to the Milky Way.

  • During this epoch, its rate of star formation would have been very high, to the point of becoming a luminous infrared galaxy for roughly 100 million years.

  • [96] While at the initial time of its discovery it was hypothesized that the brighter portion of the double nucleus is the remnant of a small galaxy “cannibalized” by the
    Andromeda Galaxy,[97] this is no longer considered a viable explanation, largely because such a nucleus would have an exceedingly short lifetime due to tidal disruption by the central black hole.

  • [109] Unlike the globular clusters of the Milky Way, which show a relatively low age dispersion, Andromeda Galaxy’s globular clusters have a much larger range of ages: from
    systems as old as the galaxy itself to much younger systems, with ages between a few hundred million years to five billion years.

  • [89] It is the co-existence of the long-known large ring-like feature in the gas of Messier 31, together with this newly discovered inner ring-like structure, offset from
    the barycenter, that suggested a nearly head-on collision with the satellite M32, a milder version of the Cartwheel encounter.

  • [85] In 1998, images from the European Space Agency’s Infrared Space Observatory demonstrated that the overall form of the Andromeda Galaxy may be transitioning into a ring
    galaxy.

  • [114] M110 also appears to be interacting with the Andromeda Galaxy, and astronomers have found in the halo of the latter a stream of metal-rich stars that appear to have
    been stripped from these satellite galaxies.

  • [118] In 2006, it was discovered that nine of the satellite galaxies lie in a plane that intersects the core of the Andromeda Galaxy; they are not randomly arranged as would
    be expected from independent interactions.

  • A likely outcome of the collision is that the galaxies will merge to form a giant elliptical galaxy[123] or perhaps even a large disc galaxy.

  • As of 2019, current calculations based on escape velocity and dynamical mass measurements put the Andromeda Galaxy at 0.8×1012 M☉,[57] which is only half of the Milky Way’s
    newer mass, calculated in 2019 at 1.5×1012 M☉.

  • In 1885, a supernova (known as S Andromedae) was seen in Andromeda, the first and so far only one observed in that galaxy.

  • The microquasar was the first observed within the Andromeda Galaxy and the first outside of the Milky Way Galaxy.

  • Arguing that a structure like the Milky Way would look like a circular nebula viewed from above and like an elliptical if viewed from an angle, he concluded that the observed
    elliptical nebulae like Andromeda, which could not be explained otherwise at the time, were indeed galaxies similar to the Milky Way.

  • This contradicted earlier measurements that seemed to indicate that the Andromeda Galaxy and Milky Way are almost equal in mass.

  • [44] Distance estimate[edit] At least four distinct techniques have been used to estimate distances from Earth to the Andromeda Galaxy.

  • [111] The most massive globular cluster in the Andromeda Galaxy, B023-G078, likely has a central intermediate black hole of almost 100,000 solar masses.

  • General The estimated distance of the Andromeda Galaxy from our own was doubled in 1953 when it was discovered that there is another, dimmer type of Cepheid variable star.

  • M32 may once have been a larger galaxy that had its stellar disk removed by M31, and underwent a sharp increase of star formation in the core region, which lasted until the
    relatively recent past.

  • Simulations show that the smaller galaxy passed through the disk of the Andromeda Galaxy along the latter’s polar axis.

  • [122] Andromeda Galaxy’s tangential or sideways velocity with respect to the Milky Way is relatively much smaller than the approaching velocity and therefore it is expected
    to collide directly with the Milky Way in about 4 billion years.

  • The halo is enriched in elements heavier than hydrogen and helium, formed from supernovae, and its properties are those expected for a galaxy that lies in the “green valley”
    of the Galaxy color–magnitude diagram (see below).

  • [78] His descriptions of the spiral structure, as each arm crosses the major axis of the Andromeda Galaxy, are as follows[79]§pp1062[80]§pp92: Since the Andromeda Galaxy is
    seen close to edge-on, it is difficult to study its spiral structure.

  • One of the explanations for this is the gravitational lensing of a red giant by a star with a mass between 0.02 and 3.6 times that of the Sun, which suggested that the star
    is likely orbited by a planet.

  • Based on current evidence, it appears that M32 underwent a close encounter with the Andromeda Galaxy in the past.

  • [110] In 2005, astronomers discovered a completely new type of star cluster in the Andromeda Galaxy.

  • The distances between the stars are, therefore, much greater within the newly discovered extended clusters.

  • As a result, some consider G1 to be the remnant core of a dwarf galaxy that was consumed by Andromeda in the distant past.

  • A number of X-ray sources, likely X-ray binary stars, within the galaxy’s central region appear as yellowish dots.

  • [74] The Third Reference Catalogue of Bright Galaxies (RC3) used this standard for Andromeda in 1991, yielding an isophotal diameter of 46.56 kiloparsecs (152,000 light-years)
    at a distance of 2.5 milliion light-years.

  • [9] The stars in this halo behave differently from the ones in Andromeda’s main galactic disc, where they show rather disorganized orbital motions as opposed to the stars
    in the main disc having more orderly orbits and uniform velocities of 200 km/s.

  • Before the galaxies merge, there is a small chance that the Solar System could be ejected from the Milky Way or join the Andromeda Galaxy.

  • Over the past 2 billion years, star formation throughout Andromeda’s disk is thought to have decreased to the point of near-inactivity.

  • This collision stripped more than half the mass from the smaller M32 and created the ring structures in Andromeda.

  • [99] The Swift BAT all-sky survey successfully detected hard X-rays coming from a region centered 6 arcseconds away from the galaxy center.

  • Baade identified two distinct populations of stars based on their metallicity, naming the young, high-velocity stars in the disk Type I and the older, red stars in the bulge
    Type II.

  • A galactic merger roughly 100 million years ago is believed to be responsible for a counter-rotating disk of gas found in the center of Andromeda as well as the presence there
    of a relatively young (100 million years old) stellar population.

  • [62] The Andromeda Galaxy is surrounded by a massive halo of hot gas that is estimated to contain half the mass of the stars in the galaxy.

  • [63][64][65][66] Luminosity estimates[edit] Compared to the Milky Way, the Andromeda Galaxy appears to have predominantly older stars with ages >7×109 years.

  • In 1888, Isaac Roberts took one of the first photographs of Andromeda, which was still commonly thought to be a nebula within our galaxy.

  • The emission above 25 keV was later found to be originating from a single source named 3XMM J004232.1+411314, and identified as a binary system where a compact object (a neutron
    star or a black hole) accretes matter from a star.

  • The nearly invisible halo stretches about a million light-years from its host galaxy, halfway to our Milky Way Galaxy.

  • [56] The radio results (similar mass to the Milky Way Galaxy) should be taken as likeliest as of 2018, although clearly this matter is still under active investigation by
    a number of research groups worldwide.

  • The dimmer concentration, P2, falls at the true center of the galaxy and contains a black hole measured at 3–5 × 107 M☉ in 1993,[92] and at 1.1–2.3 × 108 M☉ in 2005.

  • [71] This suggests that the latter once experienced a great star formation phase, but is now in a relative state of quiescence, whereas the Milky Way is experiencing more
    active star formation.

  • [9] The galaxy is inclined an estimated 77° relative to Earth (where an angle of 90° would be edge-on).

  • [17] With an apparent magnitude of 3.4, the Andromeda Galaxy is among the brightest of the Messier objects,[18] and is visible to the naked eye from Earth on moonless nights,[19]
    even when viewed from areas with moderate light pollution.

  • The Andromeda Galaxy’s dwarf galaxy population is very similar to the Milky Way’s, but the galaxies are much more numerous.

  • [49][50][51][52] In 2006, the Andromeda Galaxy’s spheroid was determined to have a higher stellar density than that of the Milky Way,[53] and its galactic stellar disk was
    estimated at about twice the diameter of that of the Milky Way.

  • Rectified images of the galaxy seem to show a fairly normal spiral galaxy, exhibiting two continuous trailing arms that are separated from each other by a minimum of about
    13,000 ly (820,000,000 AU) and that can be followed outward from a distance of roughly 1,600 ly (100,000,000 AU) from the core.

  • [72] Structure Based on its appearance in visible light, the Andromeda Galaxy is classified as an SA(s)b galaxy in the de Vaucouleurs–Sandage extended classification system
    of spiral galaxies.

  • [98] A balloon flight on 20 October 1970, set an upper limit for detectable hard X-rays from the Andromeda Galaxy.

  • The Milky Way and Andromeda galaxies are expected to collide in around 4–5 billion years,[15] merging to form a giant elliptical galaxy[16] or a large lenticular galaxy.

 

Works Cited

[‘Blue absolute magnitude of −20.89 – Color index of 0.63 = −21.52
2. ^ This is the diameter as measured though the D25 standard. The halo extends up to a distance of 67.45 kiloparsecs (220×103 ly).[9]
3. ^ J00443799+4129236 is at celestial coordinates
R.A. 00h 44m 37.99s, Dec. +41° 29′ 23.6″.
4. ^ average(787 ± 18, 770 ± 40, 772 ± 44, 783 ± 25) = ((787 + 770 + 772 + 783) / 4) ± (182 + 402 + 442 + 252)0.5 / 2 = 778 ± 33.
5. ^ Blue absolute magnitude of −21.58 (see reference) – Color index of
0.63 = absolute visual magnitude of −22.21
6. “Results for Messier 31”. NASA/IPAC Extragalactic Database. NASA/IPAC. Retrieved 28 February 2019.
7. ^ Jump up to:a b Karachentsev, Igor D.; Kashibadze, Olga 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.
8. ^ Riess, Adam G.; Fliri, Jürgen; Valls-Gabaud, David (2012).
“Cepheid Period-Luminosity Relations in the Near-Infrared and the Distance to M31 from Thehubble Space Telescopewide Field Camera 3”. The Astrophysical Journal. 745 (2): 156. arXiv:1110.3769. Bibcode:2012ApJ…745..156R. doi:10.1088/0004-637X/745/2/156.
S2CID 119113794.
9. ^ “M 31”. Retrieved 30 September 2018.
10. ^ Gil de Paz, Armando; Boissier, Samuel; Madore, Barry F.; et al. (2007). “The GALEX Ultraviolet Atlas of Nearby Galaxies”. Astrophysical Journal. 173 (2): 185–255. arXiv:astro-ph/0606440.
Bibcode:2007ApJS..173..185G. doi:10.1086/516636. S2CID 119085482.
11. ^ Jump up to:a b c Ribas, Ignasi; Jordi, Carme; Vilardell, Francesc; et al. (2005). “First Determination of the Distance and Fundamental Properties of an Eclipsing Binary in the
Andromeda Galaxy”. Astrophysical Journal Letters. 635 (1): L37–L40. arXiv:astro-ph/0511045. Bibcode:2005ApJ…635L..37R. doi:10.1086/499161. S2CID 119522151.
12. ^ “The median values of the Milky Way and Andromeda masses are MG = 0.8+0.4
−0.3×1012
M☉ and MA = 1.5+0.5
−0.4×1012 M☉ at a 68% level” Peñarrubia, Jorge; Ma, Yin-Zhe; Walker, Matthew G.; McConnachie, Alan W. (29 July 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., but compare “[we estimate] the virial mass and radius of the galaxy to be 0.8×1012 ± 0.1×1012 M☉ (1.59×1042 ± 2.0×1041 kg)” Kafle, Prajwal R.; Sharma,
Sanjib; Lewis, Geraint F.; et al. (1 February 2018). “The Need for Speed: Escape velocity and dynamical mass measurements of the Andromeda Galaxy”. Monthly Notices of the Royal Astronomical Society. 475 (3): 4043–4054. arXiv:1801.03949. Bibcode:2018MNRAS.475.4043K.
doi:10.1093/mnras/sty082. ISSN 0035-8711. S2CID 54039546.
13. ^ Jump up to:a b c 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.
14. ^ Jump up to:a b c d e Chapman, Scott C.; Ibata, Rodrigo A.; Lewis, Geraint F.; et al. (2006). “A kinematically selected, metal-poor spheroid in the outskirts of M31”. Astrophysical Journal. 653 (1): 255–266.
arXiv:astro-ph/0602604. Bibcode:2006ApJ…653..255C. doi:10.1086/508599. S2CID 14774482. Also see the press release, “Andromeda’s Stellar Halo Shows Galaxy’s Origin to Be Similar to That of Milky Way” (Press release). Caltech Media Relations. 27
February 2006. Archived from the original on 9 May 2006. Retrieved 24 May 2006.
15. ^ Young, Kelly (6 June 2006). “The Andromeda Galaxy hosts a trillion stars”. New Scientist. Retrieved 6 October 2014.
16. ^ Jump up to:a b Moskvitch, Katia (25
November 2010). “Andromeda ‘born in a collision'”. BBC News. Archived from the original on 26 November 2010. Retrieved 25 November 2010.
17. ^ Kafle, Prajwal R.; Sharma, Sanjib; Lewis, Geraint F.; et al. (1 February 2018). “The Need for Speed:
Escape velocity and dynamical mass measurements of the Andromeda Galaxy”. Monthly Notices of the Royal Astronomical Society. 475 (3): 4043–4054. arXiv:1801.03949. Bibcode:2018MNRAS.475.4043K. doi:10.1093/mnras/sty082. ISSN 0035-8711. S2CID 54039546.
18. ^
“Milky Way tips the scales at 1.5 trillion solar masses” (11 March 2019). AstronomyNow.com. Retrieved 13 July 2019.
19. ^ Mahon, Chris (20 May 2018). “New Research Says the Milky Way Is Far Bigger Than We Thought Possible.” OuterPlaces.com. Retrieved
13 July 2019.
20. ^ 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.
21. ^ “NASA’s Hubble Shows Milky Way is Destined for Head-On Collision”. NASA. 31 May 2012. Archived from the original on 4 June 2014. Retrieved
12 July 2012.
22. ^ Jump up to:a b Ueda, Junko; Iono, Daisuke; Yun, Min S.; 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.
23. ^ Frommert, Hartmut; Kronberg, Christine (22 August 2007). “Messier Object Data, sorted by Apparent Visual Magnitude”. SEDS. Archived from the original on 12 July 2007. Retrieved 27 August 2007.
24. ^
“M 31, M 32 & M 110”. 15 October 2016.
25. ^ Hafez, Ihsan (2010). Abd al-Rahman al-Sufi and his book of the fixed stars: a journey of re-discovery (Ph.D. Thesis). James Cook University. Bibcode:2010PhDT…….295H. Retrieved 23 June 2016.
26. ^
“The Andromeda Galaxy (M31): Location, Characteristics & Images”. Space.com. 10 January 2018.
27. ^ Jump up to:a b Kepple, George Robert; Sanner, Glen W. (1998). The Night Sky Observer’s Guide. Vol. 1. Willmann-Bell. p. 18. ISBN 978-0-943396-58-3.
28. ^
Davidson, Norman (1985). Astronomy and the imagination: a new approach to man’s experience of the stars. Routledge Kegan & Paul. p. 203. ISBN 978-0-7102-0371-7.
29. ^ Kant, Immanuel, Universal Natural History and Theory of the Heavens (1755)
30. ^
Herschel, William (1785). “On the Construction of the Heavens”. Philosophical Transactions of the Royal Society of London. 75: 213–266. doi:10.1098/rstl.1785.0012. S2CID 186213203.
31. ^ Huggins, William (1864). “On the Spectra of Some of the Nebulae”.
Philosophical Transactions of the Royal Society of London. 154: 437–444. Bibcode:1864RSPT..154..437H. doi:10.1098/rstl.1864.0013.
32. ^ Backhouse, Thomas W. (1888). “Nebula in Andromeda and Nova, 1885”. Monthly Notices of the Royal Astronomical
Society. 48 (3): 108–110. Bibcode:1888MNRAS..48..108B. doi:10.1093/mnras/48.3.108.
33. ^ Roberts, I. (1888). “photographs of the nebulæ M 31, h 44, and h 51 Andromedæ, and M 27 Vulpeculæ”. Monthly Notices of the Royal Astronomical Society. 49 (2):
65–66. Bibcode:1888MNRAS..49…65R. doi:10.1093/mnras/49.2.65.
34. ^ LIBRARY, ROYAL ASTRONOMICAL SOCIETY/SCIENCE PHOTO. “Andromeda Galaxy, 19th century – Stock Image – C014/5148”. Science Photo Library.
35. ^ Slipher, Vesto M. (1913). “The Radial
Velocity of the Andromeda Nebula”. Lowell Observatory Bulletin. 1 (8): 56–57. Bibcode:1913LowOB…2…56S.
36. ^ Curtis, Heber Doust (1988). “Novae in Spiral Nebulae and the Island Universe Theory”. Publications of the Astronomical Society of the
Pacific. 100: 6. Bibcode:1988PASP..100….6C. doi:10.1086/132128.
37. ^ “Two naked-eye galaxies above the VLT”. ESO Picture of the Week. Retrieved 22 October 2013.
38. ^ Öpik, Ernst (1922). “An estimate of the distance of the Andromeda Nebula”.
Astrophysical Journal. 55: 406–410. Bibcode:1922ApJ….55..406O. doi:10.1086/142680.
39. ^ Hubble, Edwin P. (1929). “A spiral nebula as a stellar system, Messier 31”. Astrophysical Journal. 69: 103–158. Bibcode:1929ApJ….69..103H. doi:10.1086/143167.
40. ^
Baade, Walter (1944). “The Resolution of Messier 32, NGC 205, and the Central Region of the Andromeda Nebula”. Astrophysical Journal. 100: 137. Bibcode:1944ApJ…100..137B. doi:10.1086/144650.
41. ^ Gribbin, John R. (2001). The Birth of Time: How
Astronomers Measure the Age of the Universe. Yale University Press. p. 151. ISBN 978-0-300-08914-1.
42. ^ Brown, Robert Hanbury; Hazard, Cyril (1950). “Radio-frequency Radiation from the Great Nebula in Andromeda (M.31)”. Nature. 166 (4230): 901–902.
Bibcode:1950Natur.166..901B. doi:10.1038/166901a0. S2CID 4170236.
43. ^ Brown, Robert Hanbury; Hazard, Cyril (1951). “Radio emission from the Andromeda nebula”. MNRAS. 111 (4): 357–367. Bibcode:1951MNRAS.111..357B. doi:10.1093/mnras/111.4.357.
44. ^
van der Kruit, Piet C.; Allen, Ronald J. (1976). “The Radio Continuum Morphology of Spiral Galaxies”. Annual Review of Astronomy and Astrophysics. 14 (1): 417–445. Bibcode:1976ARA&A..14..417V. doi:10.1146/annurev.aa.14.090176.002221.
45. ^ Ingrosso,
Gabriele; Calchi Novati, Sebastiano; De Paolis, Francesco; et al. (2009). “Pixel-lensing as a way to detect extrasolar planets in M31”. Monthly Notices of the Royal Astronomical Society. 399 (1): 219–228. arXiv:0906.1050. Bibcode:2009MNRAS.399..219I.
doi:10.1111/j.1365-2966.2009.15184.x. S2CID 6606414.
46. ^ Beck, Rainer; Berkhuijsen, Elly M.; Giessuebel, Rene; et al. (2020). “Magnetic fields and cosmic rays in M 31”. Astronomy & Astrophysics. 633: A5. arXiv:1910.09634. Bibcode:2020A&A…633A…5B.
doi:10.1051/0004-6361/201936481. S2CID 204824172.
47. ^ Holland, Stephen (1998). “The Distance to the M31 Globular Cluster System”. Astronomical Journal. 115 (5): 1916–1920. arXiv:astro-ph/9802088. Bibcode:1998AJ….115.1916H. doi:10.1086/300348.
S2CID 16333316.
48. ^ Stanek, Krzysztof Z.; Garnavich, Peter M. (1998). “Distance to M31 With the HST and Hipparcos Red Clump Stars”. Astrophysical Journal Letters. 503 (2): 131–141. arXiv:astro-ph/9802121. Bibcode:1998ApJ…503L.131S. doi:10.1086/311539.
S2CID 6383832.
49. ^ Jump up to:a b Davidge, Timothy (Tim) J.; McConnachie, Alan W.; Fardal, Mark A.; et al. (2012). “The Recent Stellar Archeology of M31 – The Nearest Red Disk Galaxy”. The Astrophysical Journal. 751 (1): 74. arXiv:1203.6081. Bibcode:2012ApJ…751…74D.
doi:10.1088/0004-637X/751/1/74. S2CID 59933737.
50. ^ Karachentsev, Igor D.; Karachentseva, Valentina E.; Huchtmeier, Walter K.; Makarov, Dmitry I. (2004). “A Catalog of Neighboring Galaxies”. Astronomical Journal. 127 (4): 2031–2068. Bibcode:2004AJ….127.2031K.
doi:10.1086/382905.
51. ^ McConnachie, Alan W.; Irwin, Michael J.; Ferguson, Annette M. N.; et al. (2005). “Distances and metallicities for 17 Local Group galaxies”. Monthly Notices of the Royal Astronomical Society. 356 (4): 979–997. arXiv:astro-ph/0410489.
Bibcode:2005MNRAS.356..979M. doi:10.1111/j.1365-2966.2004.08514.x.
52. ^ “Hubble Finds Giant Halo Around the Andromeda Galaxy”. Retrieved 14 June 2015.
53. ^ Peñarrubia, Jorge; Ma, Yin-Zhe; Walker, Matthew G.; McConnachie, Alan W. (29 July 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.
54. ^ Jump up to:a b Kafle, Prajwal
R.; Sharma, Sanjib; Lewis, Geraint F.; et al. (2018). “The need for speed: escape velocity and dynamical mass measurements of the Andromeda galaxy”. Monthly Notices of the Royal Astronomical Society. 475 (3): 4043–4054. arXiv:1801.03949. Bibcode:2018MNRAS.475.4043K.
doi:10.1093/mnras/sty082. S2CID 54039546.
55. ^ Kafle, Prajwal R.; Sharma, Sanjib; Lewis, Geraint F.; Robotham, Aaron S G.; Driver, Simon P. (2018). “The need for speed: Escape velocity and dynamical mass measurements of the Andromeda galaxy”. Monthly
Notices of the Royal Astronomical Society. 475 (3): 4043–4054. arXiv:1801.03949. Bibcode:2018MNRAS.475.4043K. doi:10.1093/mnras/sty082. S2CID 54039546.
56. ^ “Milky Way ties with neighbour in galactic arms race”. 15 February 2018.
57. ^ Science,
Samantha Mathewson 2018-02-20T19:05:26Z; Astronomy (20 February 2018). “The Andromeda Galaxy Is Not Bigger Than the Milky Way After All”. Space.com.
58. ^ Jump up to:a b Kalirai, Jasonjot Singh; Gilbert, Karoline M.; Guhathakurta, Puragra; et al.
(2006). “The Metal-Poor Halo of the Andromeda Spiral Galaxy (M31)”. Astrophysical Journal. 648 (1): 389–404. arXiv:astro-ph/0605170. Bibcode:2006ApJ…648..389K. doi:10.1086/505697. S2CID 15396448.
59. ^ Barmby, Pauline; Ashby, Matthew L. N.; Bianchi,
Luciana; et al. (2006). “Dusty Waves on a Starry Sea: The Mid-Infrared View of M31”. The Astrophysical Journal. 650 (1): L45–L49. arXiv:astro-ph/0608593. Bibcode:2006ApJ…650L..45B. doi:10.1086/508626. S2CID 16780719.
60. ^ Barmby, Pauline; Ashby,
Matthew L. N.; Bianchi, Luciana; et al. (2007). “Erratum: Dusty Waves on a Starry Sea: The Mid-Infrared View of M31”. The Astrophysical Journal. 655 (1): L61. Bibcode:2007ApJ…655L..61B. doi:10.1086/511682.
61. ^ Jump up to:a b Tamm, Antti; Tempel,
Elmo; Tenjes, Peeter; et al. (2012). “Stellar mass map and dark matter distribution in M 31”. Astronomy & Astrophysics. 546: A4. arXiv:1208.5712. Bibcode:2012A&A…546A…4T. doi:10.1051/0004-6361/201220065. S2CID 54728023.
62. ^ Kafle, Prajwal
R.; Sharma, Sanjib; Lewis, Geraint F.; Robotham, Aaron S G.; Driver, Simon P. (2018). “The Need for Speed: Escape velocity and dynamical mass measurements of the Andromeda galaxy”. Monthly Notices of the Royal Astronomical Society. 475 (3): 4043–4054.
arXiv:1801.03949. Bibcode:2018MNRAS.475.4043K. doi:10.1093/mnras/sty082. S2CID 54039546.
63. ^ Downer, Bethany; Telescope, ESA/Hubble (10 March 2019). “Hubble & Gaia Reveal Weight of the Milky Way: 1.5 Trillion Solar Masses”.
64. ^ Starr, Michelle
(8 March 2019). “The Latest Calculation of Milky Way’s Mass Just Changed What We Know About Our Galaxy”. ScienceAlert.com. Archived from the original on 8 March 2019. Retrieved 8 March 2019.
65. ^ Watkins, Laura L.; et al. (2 February 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.
66. ^ Braun, Robert; Thilker,
David A.; Walterbos, René A. M.; Corbelli, Edvige (2009). “A Wide-Field High-Resolution H I Mosaic of Messier 31. I. Opaque Atomic Gas and Star Formation Rate Density”. The Astrophysical Journal. 695 (2): 937–953. arXiv:0901.4154. Bibcode:2009ApJ…695..937B.
doi:10.1088/0004-637X/695/2/937. S2CID 17996197.
67. ^ Draine, Bruce T.; Aniano, Gonzalo; Krause, Oliver; et al. (2014). “Andromeda’s Dust”. The Astrophysical Journal. 780 (2): 172. arXiv:1306.2304. Bibcode:2014ApJ…780..172D. doi:10.1088/0004-637X/780/2/172.
S2CID 118999676.
68. ^ “HubbleSite – NewsCenter – Hubble Finds Giant Halo Around the Andromeda Galaxy (05/07/2015) – The Full Story”. hubblesite.org. Retrieved 7 May 2015.
69. ^ Gebhard, Marissa (7 May 2015). “Hubble finds massive halo around
the Andromeda Galaxy”. University of Notre Dame News.
70. ^ Lehner, Nicolas; Howk, Chris; Wakker, Bart (25 April 2014). “Evidence for a Massive, Extended Circumgalactic Medium Around the Andromeda Galaxy”. The Astrophysical Journal. 804 (2): 79.
arXiv:1404.6540. Bibcode:2015ApJ…804…79L. doi:10.1088/0004-637x/804/2/79. S2CID 31505650.
71. ^ “NASA’s Hubble Finds Giant Halo Around the Andromeda Galaxy”. 7 May 2015. Retrieved 7 May 2015.
72. ^ Jump up to:a b van den Bergh, Sidney (1999).
“The local group of galaxies”. Astronomy and Astrophysics Review. 9 (3–4): 273–318. Bibcode:1999A&ARv…9..273V. doi:10.1007/s001590050019. S2CID 119392899.
73. ^ 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.
74. ^ McCall, Marshall L. (2014). “A Council of Giants”. Monthly Notices of the Royal Astronomical
Society. 440 (1): 405–426. arXiv:1403.3667. Bibcode:2014MNRAS.440..405M. doi:10.1093/mnras/stu199. S2CID 119087190.
75. ^ Tempel, Elmo; Tamm, Antti; Tenjes, Peeter (2010). “Dust-corrected surface photometry of M 31 from Spitzer far-infrared observations”.
Astronomy and Astrophysics. 509: A91. arXiv:0912.0124. Bibcode:2010A&A…509A..91T. doi:10.1051/0004-6361/200912186. S2CID 118705514. wA91.
76. ^ Liller, William; Mayer, Ben (1987). “The Rate of Nova Production in the Galaxy”. Publications of the
Astronomical Society of the Pacific. 99: 606–609. Bibcode:1987PASP…99..606L. doi:10.1086/132021. S2CID 122526653.
77. ^ Mutch, Simon J.; Croton, Darren J.; Poole, Gregory 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.
78. ^ Beaton, Rachael L.; Majewski, Steven R.; Guhathakurta, Puragra; et al. (2006). “Unveiling the Boxy Bulge and Bar of the Andromeda
Spiral Galaxy”. Astrophysical Journal Letters. 658 (2): L91. arXiv:astro-ph/0605239. Bibcode:2007ApJ…658L..91B. doi:10.1086/514333. S2CID 889325.
79. ^ “Dimensions of Galaxies”. ned.ipac.caltech.edu.
80. ^ “Atlas of the Andromeda Galaxy”. ned.ipac.caltech.edu.
81. ^
“Astronomers Find Evidence of an Extreme Warp in the Stellar Disk of the Andromeda Galaxy” (Press release). UC Santa Cruz. 9 January 2001. Archived from the original on 19 May 2006. Retrieved 24 May 2006.
82. ^ Rubin, Vera C.; Ford, W. Kent Jr.
(1970). “Rotation of the Andromeda Nebula from a Spectroscopic Survey of Emission”. Astrophysical Journal. 159: 379. Bibcode:1970ApJ…159..379R. doi:10.1086/150317. S2CID 122756867.
83. ^ Arp, Halton (1964). “Spiral Structure in M31”. Astrophysical
Journal. 139: 1045. Bibcode:1964ApJ…139.1045A. doi:10.1086/147844.
84. ^ van den Bergh, Sidney (1991). “The Stellar Populations of M31”. Publications of the Astronomical Society of the Pacific. 103: 1053–1068. Bibcode:1991PASP..103.1053V. doi:10.1086/132925.
S2CID 249711674.
85. ^ Hodge, Paul W. (1966). Galaxies and Cosmology. McGraw Hill.
86. ^ Simien, François; Pellet, André; Monnet, Guy; et al. (1978). “The spiral structure of M31 – A morphological approach”. Astronomy and Astrophysics. 67 (1):
73–79. Bibcode:1978A&A….67…73S.
87. ^ Haas, Martin (2000). “Cold dust in M31 as mapped by ISO”. The Interstellar Medium in M31 and M33. Proceedings 232. WE-Heraeus Seminar: 69–72. Bibcode:2000immm.proc…69H.
88. ^ Walterbos, René A. M.; Kennicutt,
Robert C. Jr. (1988). “An optical study of stars and dust in the Andromeda galaxy”. Astronomy and Astrophysics. 198: 61–86. Bibcode:1988A&A…198…61W.
89. ^ Jump up to:a b Gordon, Karl D.; Bailin, J.; Engelbracht, Charles W.; et al. (2006). “Spitzer
MIPS Infrared Imaging of M31: Further Evidence for a Spiral-Ring Composite Structure”. The Astrophysical Journal. 638 (2): L87–L92. arXiv:astro-ph/0601314. Bibcode:2006ApJ…638L..87G. doi:10.1086/501046. S2CID 15495044.
90. ^ Braun, Robert (1991).
“The distribution and kinematics of neutral gas, HI region in M31”. Astrophysical Journal. 372: 54–66. Bibcode:1991ApJ…372…54B. doi:10.1086/169954.
91. ^ “ISO unveils the hidden rings of Andromeda” (Press release). European Space Agency. 14
October 1998. Retrieved 24 May 2006.
92. ^ Morrison, Heather; Caldwell, Nelson; Harding, Paul; et al. (2008). Young Star Clusters in M 31. Galaxies in the Local Volume, Astrophysics and Space Science Proceedings. Astrophysics and Space Science Proceedings.
Vol. 5. pp. 227–230. arXiv:0708.3856. Bibcode:2008ASSP….5..227M. doi:10.1007/978-1-4020-6933-8_50. ISBN 978-1-4020-6932-1. S2CID 17519849.
93. ^ Pagani, Laurent; Lequeux, James; Cesarsky, Diego; et al. (1999). “Mid-infrared and far-ultraviolet
observations of the star-forming ring of M 31”. Astronomy & Astrophysics. 351: 447–458. arXiv:astro-ph/9909347. Bibcode:1999A&A…351..447P.
94. ^ Aguilar, David A.; Pulliam, Christine (18 October 2006). “Busted! Astronomers Nab Culprit in Galactic
Hit-and-Run”. Harvard-Smithsonian Center for Astrophysics. Archived from the original on 8 October 2014. Retrieved 6 October 2014.
95. ^ Block, David L.; Bournaud, Frédéric; Combes, Françoise; et al. (2006). “An almost head-on collision as the origin
of the two off-centre rings in the Andromeda galaxy”. Nature. 443 (1): 832–834. arXiv:astro-ph/0610543. Bibcode:2006Natur.443..832B. doi:10.1038/nature05184. PMID 17051212. S2CID 4426420.
96. ^ Bullock, James S.; Johnston, Kathryn V. (2005). “Tracing
Galaxy Formation with Stellar Halos I: Methods”. Astrophysical Journal. 635 (2): 931–949. arXiv:astro-ph/0506467. Bibcode:2005ApJ…635..931B. doi:10.1086/497422. S2CID 14500541.
97. ^ Lauer, Tod R.; Faber, Sandra M.; Groth, Edward J.; et al. (1993).
“Planetary camera observations of the double nucleus of M31” (PDF). Astronomical Journal. 106 (4): 1436–1447, 1710–1712. Bibcode:1993AJ….106.1436L. doi:10.1086/116737.
98. ^ Bender, Ralf; Kormendy, John; Bower, Gary; et al. (2005). “HST STIS Spectroscopy
of the Triple Nucleus of M31: Two Nested Disks in Keplerian Rotation around a Supermassive Black Hole”. Astrophysical Journal. 631 (1): 280–300. arXiv:astro-ph/0509839. Bibcode:2005ApJ…631..280B. doi:10.1086/432434. S2CID 53415285.
99. ^ Gebhardt,
Karl; Bender, Ralf; Bower, Gary; et al. (June 2000). “A Relationship between Nuclear Black Hole Mass and Galaxy Velocity Dispersion”. The Astrophysical Journal. 539 (1): L13–L16. arXiv:astro-ph/0006289. Bibcode:2000ApJ…539L..13G. doi:10.1086/312840.
S2CID 11737403.
100. ^ Jump up to:a b Tremaine, Scott (1995). “An Eccentric-Disk Model for the Nucleus of M31”. Astronomical Journal. 110: 628–633. arXiv:astro-ph/9502065. Bibcode:1995AJ….110..628T. doi:10.1086/117548. S2CID 8408528.
101. ^
“Hubble Space Telescope Finds a Double Nucleus in the Andromeda Galaxy” (Press release). Hubble News Desk. 20 July 1993. Retrieved 26 May 2006.
102. ^ Schewe, Phillip F.; Stein, Ben (26 July 1993). “The Andromeda Galaxy has a Double Nucleus”. Physics
News Update. American Institute of Physics. Archived from the original on 15 August 2009. Retrieved 10 July 2009.
103. ^ Fujimoto, Mitsuaki; Hayakawa, Satio; Kato, Takako (1969). “Correlation between the Densities of X-Ray Sources and Interstellar
Gas”. Astrophysics and Space Science. 4 (1): 64–83. Bibcode:1969Ap&SS…4…64F. doi:10.1007/BF00651263. S2CID 120251156.
104. ^ Peterson, Laurence E. (1973). “Hard Cosmic X-Ray Sources”. In Bradt, Hale; Giacconi, Riccardo (eds.). X- and Gamma-Ray
Astronomy, Proceedings of IAU Symposium no. 55 held in Madrid, Spain, 11–13 May 1972. X- and Gamma-Ray Astronomy. Vol. 55. International Astronomical Union. pp. 51–73. Bibcode:1973IAUS…55…51P. doi:10.1007/978-94-010-2585-0_5. ISBN 978-90-277-0337-8.
105. ^
Marelli, Martino; Tiengo, Andrea; De Luca, Andrea; et al. (2017). “Discovery of periodic dips in the brightest hard X-ray source of M31 with EXTraS”. The Astrophysical Journal Letters. 851 (2): L27. arXiv:1711.05540. Bibcode:2017ApJ…851L..27M. doi:10.3847/2041-8213/aa9b2e.
S2CID 119266242.
106. ^ Barnard, Robin; Kolb, Ulrich C.; Osborne, Julian P. (2005). “Timing the bright X-ray population of the core of M31 with XMM-Newton”. arXiv:astro-ph/0508284.
107. ^ “Andromeda Galaxy Scanned with High-Energy X-ray Vision”.
Jet Propulsion Laboratory. 5 January 2016. Retrieved 22 September 2018.
108. ^ Prostak, Sergio (14 December 2012). “Microquasar in Andromeda Galaxy Amazes Astronomers”. Sci-News.com.
109. ^ “Star cluster in the Andromeda galaxy”. ESA. 4 September
2015. Retrieved 7 September 2015.
110. ^ Barmby, Pauline; Huchra, John P. (2001). “M31 Globular Clusters in the Hubble Space Telescope Archive. I. Cluster Detection and Completeness”. Astronomical Journal. 122 (5): 2458–2468. arXiv:astro-ph/0107401.
Bibcode:2001AJ….122.2458B. doi:10.1086/323457. S2CID 117895577.
111. ^ “Hubble Spies Globular Cluster in Neighboring Galaxy” (Press release). Hubble news desk STSci-1996-11. 24 April 1996. Archived from the original on 1 July 2006. Retrieved 26
May 2006.
112. ^ Meylan, Georges; Sarajedini, Ata; Jablonka, Pascale; et al. (2001). “G1 in M31 – Giant Globular Cluster or Core of a Dwarf Elliptical Galaxy?”. Astronomical Journal. 122 (2): 830–841. arXiv:astro-ph/0105013. Bibcode:2001AJ….122..830M.
doi:10.1086/321166. S2CID 17778865.
113. ^ Ma, Jun; de Grijs, Richard; Yang, Yanbin; et al. (2006). “A ‘super’ star cluster grown old: the most massive star cluster in the Local Group”. Monthly Notices of the Royal Astronomical Society. 368 (3):
1443–1450. arXiv:astro-ph/0602608. Bibcode:2006MNRAS.368.1443M. doi:10.1111/j.1365-2966.2006.10231.x. S2CID 15947017.
114. ^ Cohen, Judith G. (2006). “The Not So Extraordinary Globular Cluster 037-B327 in M31” (PDF). The Astrophysical Journal. 653
(1): L21–L23. arXiv:astro-ph/0610863. Bibcode:2006ApJ…653L..21C. doi:10.1086/510384. S2CID 1733902.
115. ^ Burstein, David; Li, Yong; Freeman, Kenneth C.; et al. (2004). “Globular Cluster and Galaxy Formation: M31, the Milky Way, and Implications
for Globular Cluster Systems of Spiral Galaxies”. Astrophysical Journal. 614 (1): 158–166. arXiv:astro-ph/0406564. Bibcode:2004ApJ…614..158B. doi:10.1086/423334. S2CID 56003193.
116. ^ Huxor, Avon P.; Tanvir, Nial R.; Irwin, Michael J.; et al.
(2005). “A new population of extended, luminous, star clusters in the halo of M31”. Monthly Notices of the Royal Astronomical Society. 360 (3): 993–1006. arXiv:astro-ph/0412223. Bibcode:2005MNRAS.360.1007H. doi:10.1111/j.1365-2966.2005.09086.x. S2CID
6215035.
117. ^ Pechetti, Renuka; Seth, Anil; Kamann, Sebastian; Caldwell, Nelson; Strader, Jay (January 2022). “Detection of a 100,000 M ⊙ black hole in M31’s Most Massive Globular Cluster: A Tidally Stripped Nucleus”. The Astrophysical Journal.
924 (2): 13. Bibcode:2022ApJ…924…48P. doi:10.3847/1538-4357/ac339f. S2CID 245876938.
118. ^ Higgs, C. R.; McConnachie, A. W. (2021). “Solo dwarfs IV: Comparing and contrasting satellite and isolated dwarf galaxies in the Local Group”. Monthly
Notices of the Royal Astronomical Society. 506 (2): 2766–2779. doi:10.1093/mnras/stab1754.
119. ^ Bekki, Kenji; Couch, Warrick J.; Drinkwater, Michael J.; et al. (2001). “A New Formation Model for M32: A Threshed Early-type Spiral?”. Astrophysical
Journal Letters. 557 (1): L39–L42. arXiv:astro-ph/0107117. Bibcode:2001ApJ…557L..39B. doi:10.1086/323075. S2CID 18707442.
120. ^ Ibata, Rodrigo A.; Irwin, Michael J.; Lewis, Geraint F.; et al. (2001). “A giant stream of metal-rich stars in the
halo of the galaxy M31”. Nature. 412 (6842): 49–52. arXiv:astro-ph/0107090. Bibcode:2001Natur.412…49I. doi:10.1038/35083506. PMID 11452300. S2CID 4413139.
121. ^ Young, Lisa M. (2000). “Properties of the Molecular Clouds in NGC 205”. Astronomical
Journal. 120 (5): 2460–2470. arXiv:astro-ph/0007169. Bibcode:2000AJ….120.2460Y. doi:10.1086/316806. S2CID 18728927.
122. ^ Rudenko, Pavlo; Worthey, Guy; Mateo, Mario (2009). “Intermediate age clusters in the field containing M31 and M32 stars”.
The Astronomical Journal. 138 (6): 1985–1989. Bibcode:2009AJ….138.1985R. doi:10.1088/0004-6256/138/6/1985.
123. ^ “Messier Object 33”. www.messier.seds.org. Retrieved 21 May 2021.
124. ^ Koch, Andreas; Grebel, Eva K. (March 2006). “The Anisotropic
Distribution of M31 Satellite Galaxies: A Polar Great Plane of Early-type Companions”. Astronomical Journal. 131 (3): 1405–1415. arXiv:astro-ph/0509258. Bibcode:2006AJ….131.1405K. doi:10.1086/499534. S2CID 3075266.
125. ^ An, Jin H.; Evans, N.
W.; Kerins, E.; Baillon, P.; Calchi Novati, S.; Carr, B. J.; Creze, M.; Giraud‐Heraud, Y.; Gould, A.; Hewett, P.; Jetzer, Ph.; Kaplan, J.; Paulin‐Henriksson, S.; Smartt, S. J.; Tsapras, Y.; Valls‐Gabaud, D. (2004). “The Anomaly in the Candidate Microlensing
Event PA‐99‐N2”. The Astrophysical Journal. 601 (2): 845–857. arXiv:astro-ph/0310457. Bibcode:2004ApJ…601..845A. doi:10.1086/380820. ISSN 0004-637X. S2CID 8312033.
126. ^ Cowen, Ron (2012). “Andromeda on collision course with the Milky Way”. Nature.
doi:10.1038/nature.2012.10765. S2CID 124815138.
127. ^ O’Callaghan, Jonathan (14 May 2018). “Apart from Andromeda, are any other galaxies moving towards us?”. Space Facts. Retrieved 3 April 2016.
128. ^ Cox, Thomas J.; Loeb, Abraham (2008). “The
collision between the Milky Way and Andromeda”. Monthly Notices of the Royal Astronomical Society. 386 (1): 461–474. arXiv:0705.1170. Bibcode:2008MNRAS.386..461C. doi:10.1111/j.1365-2966.2008.13048.x. S2CID 14964036.
129. ^ Cain, Fraser (2007).
“When Our Galaxy Smashes Into Andromeda, What Happens to the Sun?”. Universe Today. Archived from the original on 17 May 2007. Retrieved 16 May 2007.
130. ^ Plait, Phil (1 January 2014). “Yes, That Picture of the Moon and the Andromeda Galaxy Is
About Right”. Slate Magazine. Retrieved 29 July 2022.
131. ^ “Andromeda and the Moon collage”. www.noirlab.edu. Retrieved 29 July 2022.
132. ^ “Can you see other galaxies without a telescope?”. starchild.gsfc.nasa.gov.
133. ^ “Tonight, Find
the Andromeda Galaxy”. 18 September 2019.
134. ^ King, Bob (9 September 2015). “How to See the Farthest Thing You Can See”. Sky & Telescope.
135. ^ Garner, Rob (20 February 2019). “Messier 33 (The Triangulum Galaxy)”. NASA. Retrieved 6 August
2021.
136. ^ Harrington, Philip S. (2010). Cosmic Challenge: The Ultimate Observing List for Amateurs. Cambridge University Press. pp. 28–29. ISBN 9781139493680. But can [M81’s] diffuse 7.9-magnitude glow actually be glimpsed without any optical
aid? The answer is yes, but with a few important qualifications. Not only must the observing site be extraordinarily dark and completely absent of any atmospheric interferences, either natural or artificial, but the observer must have exceptionally
keen vision.
137. ^ “M31.html”. www.physics.ucla.edu.
138. ^ King, Bob (16 September 2015). “Watch Andromeda Blossom in Binoculars”. Sky & Telescope.
139. ^ “Observing M31, the Andromeda Galaxy”.
140. ^ “Globular Clusters in the Andromeda
Galaxy”. www.astronomy-mall.com.
Photo credit: https://www.flickr.com/photos/olibac/3517492544/’]