The Milky Way's Galactic Center in the night sky above the Paranal Observatory (the laser creates a guide-star for the telescope).
The Milky Way is the galaxy[nb 1] that contains our Solar System. The descriptor "milky" is derived from the galaxy's appearance from Earth: a band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye. The term Milky Way is a translation of the Latin via lactea, from the Greek γαλαξίας κύκλος (galaxías kýklos, "milky circle"). From Earth, the Milky Way appears as a band because its disk-shaped structure is viewed from within. 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. Following the 1920 Great Debate between the astronomers Harlow Shapley and Heber Curtis, observations by Edwin Hubble showed that the Milky Way is just one of many galaxies. The Milky Way is a barred spiral galaxy with a diameter between 150,000 and 200,000 light-years (ly). It is estimated to contain 100–400 billion stars. There are probably at least 100 billion planets in the Milky Way. The Solar System is located within the disk, 26,490 (± 100) light-years from the Galactic Center, 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*, likely a supermassive black hole of 4.100 (± 0.034) million solar masses.
Stars and gases at a wide range of distances from the Galactic Center orbit at approximately 220 kilometers per second. The constant rotation speed contradicts the laws of Keplerian dynamics and suggests that much of the mass of the Milky Way does not emit or absorb electromagnetic radiation. This mass has been termed "dark matter". The rotational period is about 240 million years at the position of the Sun. The Milky Way as a whole is moving at a velocity of approximately 600 km per second with respect to extragalactic frames of reference. 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.
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. It should be visible if the limiting magnitude is approximately +5.1 or better and shows a great deal of detail at +6.1. 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.[nb 2] "The new world atlas of artificial night sky brightness" shows that more than one-third of Earth's population cannot see the Milky Way from their homes due to light pollution.
The galactic plane is inclined by about 60° to the ecliptic (the plane of Earth's orbit). Relative to the celestial equator, it passes as far north as the constellation of Cassiopeia and as far south as the constellation of Crux, indicating the high inclination of Earth’s equatorial plane and the plane of the ecliptic, relative to the galactic plane. The north galactic pole is situated at right ascension 12h 49m, declination +27.4° (B1950) near β Comae Berenices, and the south galactic pole is near α Sculptoris. Because of this high inclination, depending on the time of night and year, the arch of the Milky Way may appear relatively low or relatively high in the sky. For observers from latitudes approximately 65° north to 65° south, the Milky Way passes directly overhead twice a day.
The Milky Way is the second-largest galaxy in the Local Group, with its stellar disk approximately 100,000 ly (30 kpc) in diameter and, on average, approximately 1,000 ly (0.3 kpc) thick. 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 the size of the contiguous United States. A ring-like filament of stars wrapping around the Milky Way may belong to the Milky Way itself, rippling above and below the relatively flat galactic plane. If so, that would mean a diameter of 150,000–180,000 light-years (46–55 kpc).
Much of the mass of the Milky Way appears to be dark matter, an unknown and invisible form of matter that interacts gravitationally with ordinary matter. A dark matter halo is 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 1–1.5×1012 M☉. Recent studies indicate a range in mass, as large as 4.5×1012 M☉  and as small as 8×1011 M☉.
The Milky Way consists of a bar-shaped core region surrounded by a disk of gas, dust and stars. 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 suspect that the Milky Way is a barred spiral galaxy, rather than an ordinary spiral galaxy, in the 1960s. Their suspicions were confirmed by the Spitzer Space Telescope observations in 2005 that showed the Milky Way's central bar to be larger than previously thought.
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. This concentration of mass is best explained as a supermassive black hole[nb 4] (SMBH) with an estimated mass of 4.1–4.5 million times the mass of the Sun. The rate of accretion of the SMBH is consistent with an inactive galactic nucleus, being estimated at around 6995100000000000000♠1×10−5 M☉ y−1. Observations indicate that there are SMBH located near the center of most normal galaxies.
The satellite galaxies surrounding the Milky way are not randomly distributed, but seemed to be the result of a break-up of some larger system producing a ring structure 500,000 light years in diameter and 50,000 light years wide. Close encounters between galaxies, like that expected in 4 billion years with the Andromeda Galaxy rips 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.
↑ These estimates are very uncertain, as most non-star objects are hard to detect; for example, black hole estimates range from ten million to one billion.
↑ For a photo see: "Sagittarius A*: Milky Way monster stars in cosmic reality show". Chandra X-ray Observatory. Harvard-Smithsonian Center for Astrophysics. January 6, 2003. Archived from the original on March 17, 2008. Retrieved May 20, 2012.
1 2 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.
↑ 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.
1 2 Rix, Hans-Walter; Bovy, Jo (2013). "The Milky Way's Stellar Disk". The Astronomy and Astrophysics Review. 21. arXiv:1301.3168. Bibcode:2013A&ARv..21...61R. doi:10.1007/s00159-013-0061-8.
↑ Odenwald, S. (March 17, 2014). "Counting the Stars in the Milky Way". The Huffington Post. Archived from the original on August 1, 2014. Retrieved June 9, 2014.
1 2 3 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.
1 2 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.
↑ 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.
1 2 3 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.
↑ 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.
1 2 3 4 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.
1 2 3 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.
1 2 3 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: 30. arXiv:1611.09144. Bibcode:2017ApJ...837...30G. doi:10.3847/1538-4357/aa5c41.
1 2 Gerhard, O. "Pattern speeds in the Milky Way". arXiv:1003.2489v1.
1 2 Harper, Douglas. "galaxy". Online Etymology Dictionary. Archived from the original on May 27, 2012. Retrieved May 20, 2012.
↑ 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.
↑ Schiller, Jon (2010). Big Bang & Black Holes. CreateSpace. p. 163. ISBN 978-1-4528-6552-2. Archived from the original on November 20, 2016.
↑ "Milky Way Galaxy: Facts About Our Galactic Home". Space.com. Archived from the original on March 21, 2017. Retrieved April 8, 2017.
↑ Hall, Shannon (May 4, 2015). "Size of the Milky Way Upgraded, Solving Galaxy Puzzle". Space.com. Archived from the original on June 7, 2015. Retrieved June 9, 2015.
1 2 3 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.
1 2 Staff (January 2, 2013). "100 Billion Alien Planets Fill Our Milky Way Galaxy: Study". Space.com. Archived from the original on January 3, 2013. Retrieved January 3, 2013.
1 2 3 Koupelis, Theo; Kuhn, Karl F. (2007). In Quest of the Universe. Jones & Bartlett Publishers. p. 492; Figure 16–13. ISBN 978-0-7637-4387-1.
1 2 H.E. Bond; E. P. Nelan; D. A. VandenBerg; G. H. Schaefer; et al. (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.
↑ "Laniakea: Our home supercluster". youtube.com. 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.
↑ 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 978-0395248300.
↑ Pasachoff, Jay M.; Filippenko, Alex (2013). The Cosmos: Astronomy in the New Millennium. Cambridge University Press. p. 384. ISBN 9781107687561. Archived from the original on December 2, 2017.
↑ Crumey, Andrew (2014). "Human contrast threshold and astronomical visibility". Monthly Notices of the Royal Astronomical Society. 442 (3): 2600–19. arXiv:1405.4209. Bibcode:2014MNRAS.442.2600C. doi:10.1093/mnras/stu992.
↑ Steinicke, Wolfgang; Jakiel, Richard (2007). Galaxies and how to observe them. Astronomers' observing guides. Springer. p. 94. ISBN 978-1-85233-752-0. Archived from the original on November 20, 2016.
↑ 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. 2 (6): e1600377. arXiv:1609.01041. Bibcode:2016SciA....2E0377F. doi:10.1126/sciadv.1600377. ISSN 2375-2548. PMC 4928945. PMID 27386582. Archived from the original on July 11, 2016.
↑ 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.
↑ "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.
↑ 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.
↑ 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: 137–148. arXiv:0902.3913. Bibcode:2009ApJ...700..137R. doi:10.1088/0004-637X/700/1/137.
↑ Gnedin, O. Y.; et al. (2010). "The mass profile of the Galaxy to 80 kpc". The Astrophysical Journal. 720: L108–L112. arXiv:1005.2619. Bibcode:2010ApJ...720L.108G. doi:10.1088/2041-8205/720/1/L108.
1 2 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.
↑ Slobodan Ninković (April 2017). "Mass Distribution and Gravitational Potential of the Milky Way". Open Astronomy. 26: 1–6. Bibcode:2017OAst...26....1N. doi:10.1515/astro-2017-0002. Archived from the original on April 22, 2017.
↑ 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): 12. arXiv:1306.4013. Bibcode:2013ApJ...775..102P. doi:10.1088/0004-637X/775/2/102. 102.
↑ Kafle, Prajwal Raj; et al. (October 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. 59.
1 2 3 "The Interstellar Medium". Archived from the original on April 19, 2015. Retrieved May 2, 2015.
1 2 "Lecture Seven: The Milky Way: Gas" (PDF). Archived (PDF) from the original on July 8, 2015. Retrieved May 2, 2015.
↑ 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.
↑ 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.
↑ 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. Retrieved 5 April 2018.
↑ "Black Holes | Science Mission Directorate". NASA. Retrieved 5 April 2018.
1 2 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.
↑ 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.
↑ 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.
↑ 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.
↑ Borenstein, Seth (February 19, 2011). "Cosmic census finds crowd of planets in our galaxy". The Washington Post. Associated Press. Archived from the original on February 22, 2011.
↑ 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.
↑ Overbye, Dennis (November 4, 2013). "Far-Off Planets Like the Earth Dot the Galaxy". 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. Archived from the original on November 9, 2013. Retrieved November 5, 2013.
↑ 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; 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.
1 2 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.
1 2 Kiss, Cs; Moór, A.; Tóth, L. V. (April 2004). "Far-infrared loops in the 2nd Galactic Quadrant". Astronomy and Astrophysics. 418: 131–141. arXiv:astro-ph/0401303. Bibcode:2004A&A...418..131K. doi:10.1051/0004-6361:20034530.
↑ van Woerden, Hugo; Strom, Richard G. (June 2006). "The beginnings of radio astronomy in the Netherlands" (PDF). Journal of Astronomical History and Heritage. 9 (1): 3–20. Bibcode:2006JAHH....9....3V. Archived (PDF) from the original on September 19, 2010.
↑ 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.
1 2 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: 95–107. arXiv:0903.0946. Bibcode:2009A&A...498...95V. doi:10.1051/0004-6361/20078472.
1 2 3 4 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: L72–L76. arXiv:1005.0385. Bibcode:2010ApJ...720L..72S. doi:10.1088/2041-8205/720/1/L72.
↑ 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.
1 2 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.
1 2 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.
↑ 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. 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 978-0199692293. 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.
↑ 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.
↑ 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. arXiv:astro-ph/0502058. Bibcode:2005ApJ...621L.105N. 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.
↑ Staff (September 12, 2005). "Introduction: Galactic Ring Survey". Boston University. Archived from the original on July 13, 2007. Retrieved May 10, 2007.
↑ Overbye, Dennis (November 9, 2010). "Bubbles of Energy Are Found in Galaxy". The New York Times. Archived from the original on January 10, 2016.
↑ 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.
↑ 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.
1 2 3 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: 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.
1 2 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.
1 2 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.
↑ 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.
↑ "Massive stars mark out Milky Way's 'missing' arms" Archived December 18, 2013, at the Wayback Machine., University of Leeds. December 17, 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.
1 2 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.
1 2 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.
↑ "Milky Way's Inner Beauty Revealed". Harvard-Smithsonian Center for Astrophysics. 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". Astronomy Letters. 35 (9): 609–624. arXiv:0902.3353. Bibcode:2009AstL...35..609M. doi:10.1134/s1063773709090047.
↑ Mel'Nik, A. (2005). "Outer pseudoring in the galaxy". Astronomische Nachrichten. 326 (7): 589–605. arXiv:astro-ph/0510569. Bibcode:2005AN....326Q.599M. doi:10.1002/asna.200585006.
↑ Lopez-Corredoira, M.; et al. (July 2012). "Comments on the "Monoceros" affair". arXiv:1207.2749 [astro-ph.GA].
↑ 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.
↑ 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.
↑ 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.
↑ "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: L24. arXiv:1105.2523. Bibcode:2011ApJ...734L..24D. doi:10.1088/2041-8205/734/1/l24.
↑ 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.
↑ Boen, Brooke. "NASA's Chandra Shows Milky Way is Surrounded by Halo of Hot Gas09.24.12". 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: L8. arXiv:1205.5037. Bibcode:2012ApJ...756L...8G. doi:10.1088/2041-8205/756/1/L8.
↑ "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 Communications. Archived from the original on October 29, 2012. Retrieved October 28, 2012.
1 2 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.
↑ 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.
↑ 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.
↑ 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. 7. Bibcode:2008IJAsB...7...17G. doi:10.1017/S1473550408004047.
↑ 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.
↑ 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". Archived from the original on September 7, 2015.
↑ Peter Schneider (2006). Extragalactic Astronomy and Cosmology. Springer. p. 4, Figure 1.4. ISBN 978-3-540-33174-2.
↑ Jones, Mark H.; Lambourne, Robert J.; Adams, David John (2004). An Introduction to Galaxies and Cosmology. Cambridge University Press. p. 21; Figure 1.13. ISBN 978-0-521-54623-2.
↑ Peter Schneider (2006). Extragalactic Astronomy and Cosmology. Springer. p. 413. ISBN 978-3-540-33174-2.
1 2 Staff (July 27, 2017). "Milky Way's origins are not what they seem". Phys.org. Archived from the original on July 27, 2017. Retrieved July 27, 2017.
↑ Lockman, F. J.; et al. (2008). "The Smith Cloud: A High-Velocity Cloud Colliding with the Milky Way". The Astrophysical Journal. 679: L21–L24. arXiv:0804.4155. Bibcode:2008ApJ...679L..21L. doi:10.1086/588838.
↑ 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.
↑ 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.
↑ 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.
↑ "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.
↑ 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.
1 2 Frebel, A.; et al. (2007). "Discovery of HE 1523-0901, a strongly r-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.
↑ 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.
↑ 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.
↑ R. Brent Tully; Helene Courtois; Yehuda Hoffman; Daniel Pomarède (September 2, 2014). "The Laniakea supercluster of galaxies". Nature (published September 4, 2014). 513 (7516): 71–73. arXiv:1409.0880. Bibcode:2014Natur.513...71T. doi:10.1038/nature13674. PMID 25186900.
↑ 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: 170–194. arXiv:astro-ph/0209127. Bibcode:2003ApJ...586..170P. doi:10.1086/344477.
↑ 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.
↑ 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.
↑ Lea Kivivali (June 11, 2014). "Nearby satellite galaxies challenge standard model of galaxy formation". Swinburne University of Technology. Archived from the original on March 16, 2015.
↑ Pawlowski; et al. (June 10, 2014). "Co-orbiting satellite galaxy structures are still in conflict with the distribution of primordial dwarf galaxies". Monthly Notices of the Royal Astronomical Society. 442 (3): 2362–2380. arXiv:1406.1799. Bibcode:2014MNRAS.442.2362P. doi:10.1093/mnras/stu1005.
↑ 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.
↑ Mark H. Jones; Robert J. Lambourne; David John Adams (2004). An Introduction to Galaxies and Cosmology. Cambridge University Press. p. 298. ISBN 978-0-521-54623-2.
↑ 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.
↑ 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.
1 2 Kogut, A.; et al. (1993). "Dipole anisotropy in the COBE differential microwave radiometers first-year sky maps". The Astrophysical Journal. 419: 1. arXiv:astro-ph/9312056. Bibcode:1993ApJ...419....1K. doi:10.1086/173453.
↑ 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.
↑ MacBeath, Alastair (1999). Tiamat's Brood: An Investigation Into the Dragons of Ancient Mesopotamia. Dragon's Head. p. 41. ISBN 9780952438755.
↑ James, E. O. (1963). The Worship of the Skygod: A Comparative Study in Semitic and Indo-European Religion. Jordan Lectures in Comparative religion. London, England: University of London. pp. 24, 27f.
1 2 Lambert, W. G. (1964). "Bulletin of the School of Oriental and African Studies". 27 (1). London, England: University of London: 157–158.
↑ Simpson, John; Weiner, Edmund, eds. (March 30, 1989). The Oxford English Dictionary (2nd ed.). Oxford University Press. ISBN 978-0198611868. See the entries for "Milky Way" and "galaxy".
1 2 3 4 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.
1 2 3 4 Pache, Corinne Ondine (2010). "Hercules". In Gargarin, Michael; Fantham, Elaine. Ancient Greece and Rome. 1: Academy-Bible. Oxford, England: Oxford University Press. p. 400. ISBN 978-0-19-538839-8.
↑ 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 978-1890482930. Archived from the original on November 20, 2016.
↑ 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."
↑ (Aristotle with Ross, 1931), p. 41: Archived April 11, 2016, at the Wayback Machine. "For it is natural to suppose that, if the motion of a single star excites a flame, that of all the stars should have a similar result, and especially in that region in which the stars are biggest and most numerous and nearest to one another."
↑ (Aristotle with Ross, 1931), p. 43 : Archived April 11, 2016, at the Wayback Machine. "We have now explained the phenomena that occur in that part of the terrestrial world which is continuous with the motions of the heavens, namely, shooting-stars and the burning flame, comets and the milky way, these being the chief affections that appear in that region."
1 2 Montada, Josep Puig (September 28, 2007). "Ibn Bajja". Stanford Encyclopedia of Philosophy. Archived from the original on July 28, 2012. Retrieved July 11, 2008.
↑ Heidarzadeh, Tofigh (2008). A history of physical theories of comets, from Aristotle to Whipple. Springer. pp. 23–25. ISBN 978-1-4020-8322-8.
↑ 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 . doi:10.2307/600445. JSTOR 600445.
↑ Galileo Galilei, Sidereus Nuncius (Venice, (Italy): Thomas Baglioni, 1610), pages 15 and 16. Archived March 16, 2016, at the Wayback Machine.
English translation: Galileo Galilei with Edward Stafford Carlos, trans., The Sidereal Messenger (London, England: Rivingtons, 1880), pages 42 and 43. Archived December 2, 2012, at the Wayback Machine.
↑ O'Connor, J. J.; Robertson, E. F. (November 2002). "Galileo Galilei". University of St. Andrews. Archived from the original on May 30, 2012. Retrieved January 8, 2007.
↑ Evans, J. C. (November 24, 1998). "Our Galaxy". George Mason University. Archived from the original on June 30, 2012. Retrieved January 4, 2007.
The Royal Society of London Archived April 6, 2016, at the Wayback Machine.
↑ 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. Archived from the original on June 4, 2012. Retrieved January 5, 2007.
↑ Sandage, Allan (1989). "Edwin Hubble, 1889–1953". Journal of the Royal Astronomical Society of Canada. 83 (6). Bibcode:1989JRASC..83..351S.
↑ "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.