Editing Andromeda Galaxy (section)

== References ==
{{reflist|refs=
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<ref name="milky-way-collide">{{cite web | title = NASA's Hubble Shows Milky Way is Destined for Head-On Collision | publisher = NASA | date = 31 May 2012 | url = http://www.nasa.gov/mission_pages/hubble/science/milky-way-collide.html | access-date = 12 July 2012 | archive-url = https://web.archive.org/web/20140604191905/http://www.nasa.gov/mission_pages/hubble/science/milky-way-collide.html | archive-date = 4 June 2014}}</ref>
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<ref name="Huggins & Miller 1864">{{cite journal | last = Huggins | first = William | author-link=William Huggins<!-- "A Supplement to On the Spectra of Some of the Fixed Stars, by Huggins and | last2 = Miller | first2 = William A. --> | date = 1864 | title = On the Spectra of Some of the Nebulae | journal = [[Philosophical Transactions of the Royal Society of London]] | volume = 154 | pages = 437–444 | doi = 10.1098/rstl.1864.0013 | bibcode = 1864RSPT..154..437H | doi-access = free}}</ref>
<ref name="Backhouse 1888">{{cite journal | last = Backhouse | first = Thomas W. | date = 1888 | title = Nebula in Andromeda and Nova, 1885 | journal = [[Monthly Notices of the Royal Astronomical Society]] | volume = 48 | issue = 3 | pages = 108–110 | bibcode = 1888MNRAS..48..108B | doi =10.1093/mnras/48.3.108 | doi-access = free}}</ref>
<ref name="Slipher 1913">{{cite journal | last = Slipher | first = Vesto M. | author-link=Vesto Slipher | date = 1913 | title = The Radial Velocity of the Andromeda Nebula | journal = [[Lowell Observatory Bulletin]] | volume = 1 | issue = 8 | pages = 56–57 | bibcode = 1913LowOB...2...56S}}</ref>
<ref name="Curtis 1988">{{cite journal | last = Curtis | first = Heber Doust | author-link=Heber Doust Curtis | date = 1988 | title = Novae in Spiral Nebulae and the Island Universe Theory | journal = [[Publications of the Astronomical Society of the Pacific]] | volume = 100 | pages = 6 | bibcode = 1988PASP..100....6C | doi = 10.1086/132128 | doi-access = free}}</ref>
<ref name="Öpik 1922">{{cite journal | last = Öpik | first = Ernst | author-link=Ernst Öpik | date = 1922 | title = An estimate of the distance of the Andromeda Nebula | journal = [[Astrophysical Journal]] | volume = 55 | pages = 406–410 | bibcode = 1922ApJ....55..406O | doi = 10.1086/142680}}</ref>
<ref name="Hubble 1929">{{cite journal | last = Hubble | first = Edwin P. | author-link=Edwin Hubble | date = 1929 | title = A spiral nebula as a stellar system, Messier 31 | journal = [[Astrophysical Journal]] | volume = 69 | pages = 103–158 | bibcode = 1929ApJ....69..103H | doi = 10.1086/143167| doi-access = free }}</ref>
<ref name="Baade 1944">{{cite journal | last = Baade | first = Walter | author-link=Walter Baade | date = 1944 | title = The Resolution of Messier 32, NGC 205, and the Central Region of the Andromeda Nebula | journal = [[Astrophysical Journal]] | volume = 100 | pages = 137 | bibcode = 1944ApJ...100..137B | doi = 10.1086/144650| doi-access = free }}</ref>
<ref name="Gribbin 2001">{{cite book | last = Gribbin | first = John R. | date = 2001 | title = The Birth of Time: How Astronomers Measure the Age of the Universe | page = 151 | publisher = [[Yale University Press]] | isbn = 978-0-300-08914-1}}</ref>
<ref name="Brown & Hazard 1950">{{cite journal | last1 = Brown | first1 = Robert Hanbury | last2 = Hazard | first2 = Cyril | date = 1950 | title = Radio-frequency Radiation from the Great Nebula in Andromeda (M.31) | journal = [[Nature (journal)|Nature]] | volume = 166 | pages = 901–902 | bibcode = 1950Natur.166..901B | doi = 10.1038/166901a0 | issue = 4230 | s2cid = 4170236}}</ref>
<ref name="Brown & Hazard 1951">{{cite journal | last1 = Brown | first1 = Robert Hanbury | last2 = Hazard | first2 = Cyril | date = 1951 | title = Radio emission from the Andromeda nebula | journal = [[MNRAS]] | volume = 111 | issue = 4 | pages = 357–367 | bibcode = 1951MNRAS.111..357B | doi=10.1093/mnras/111.4.357 | doi-access = free}}</ref>
<ref name="van der Kruit & Allen 1976">{{cite journal | last1 = van der Kruit | first1 = Piet C. | last2 = Allen | first2 = Ronald J. | date = 1976 | title = The Radio Continuum Morphology of Spiral Galaxies | journal = [[Annual Review of Astronomy and Astrophysics]] | volume = 14 | issue = 1 | pages = 417–445 | doi = 10.1146/annurev.aa.14.090176.002221 | bibcode = 1976ARA&A..14..417V}}</ref>
<ref name="Ingrosso 2009">{{cite journal | last1 = Ingrosso | first1 = Gabriele | last2 = Calchi Novati | first2 = Sebastiano | last3 = De Paolis | first3 = Francesco | display-authors=3 | last4 = Jetzer | first4 = Philippe | last5 = Nucita | first5 = Achille A. | last6 = Zakharov | first6 = Alexander F. | date = 2009 | title = Pixel-lensing as a way to detect extrasolar planets in M31 | journal = [[Monthly Notices of the Royal Astronomical Society]] | volume = 399 | issue = 1 | pages = 219–228 | arxiv = 0906.1050 | doi = 10.1111/j.1365-2966.2009.15184.x | doi-access = free | bibcode = 2009MNRAS.399..219I | s2cid = 6606414}}</ref>
<ref name="Beck 2020">{{cite journal | last1 = Beck | first1 = Rainer | last2 = Berkhuijsen | first2 = Elly M. | last3 = Giessuebel | first3 = Rene | display-authors=3 | last4 = Mulcahy | first4 = David D. | date = 2020 | title = Magnetic fields and cosmic rays in M 31 | journal = [[Astronomy & Astrophysics]] | volume = 633 | pages = A5 | arxiv = 1910.09634 | doi = 10.1051/0004-6361/201936481 | bibcode = 2020A&A...633A...5B | s2cid = 204824172}}</ref>
<ref name="Holland 1998">{{cite journal | last = Holland | first = Stephen | date = 1998 | title = The Distance to the M31 Globular Cluster System | journal = [[Astronomical Journal]] | volume = 115 | issue = 5 | pages = 1916–1920 | bibcode = 1998AJ....115.1916H | doi = 10.1086/300348 | arxiv = astro-ph/9802088 | s2cid = 16333316}}</ref>
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<ref name="Beaton 2006">{{Cite journal |last1=Beaton |first1=Rachael L. |last2=Majewski |first2=Steven R. |last3=Guhathakurta |first3=Puragra |last4=Skrutskie |first4=Michael F. |last5=Cutri |first5=Roc M. |last6=Good |first6=John |last7=Patterson |first7=Richard J. |last8=Athanassoula |first8=E. |last9=((Bureau)) |first9=Martin |display-authors=3 |date=2007-04-01 |title=Unveiling the Boxy Bulge and Bar of the Andromeda Spiral Galaxy |url=https://iopscience.iop.org/article/10.1086/514333 |journal=The Astrophysical Journal |language=en |volume=658 |issue=2 |pages=L91–L94 |arxiv=astro-ph/0605239 |bibcode=2007ApJ...658L..91B |doi=10.1086/514333 |issn=0004-637X |s2cid=889325}}</ref>
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<ref name="hubblesite 1993-07-20">{{cite press release | date = 20 July 1993 | title = Hubble Space Telescope Finds a Double Nucleus in the Andromeda Galaxy | url = https://hubblesite.org/contents/news-releases/1993/news-1993-18.html | publisher = Hubble News Desk | access-date = 26 May 2006}}</ref>
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<ref name="Marelli et al. 2017">{{cite journal | last1=Marelli | first1=Martino | last2=Tiengo | first2=Andrea | last3=De Luca | first3=Andrea | display-authors=3 | last4=Salvetti | first4=David | last5=Saronni | first5=Luca | last6=Sidoli | first6=Lara | last7=Paizis | first7=Adamantia | last8=Salvaterra | first8=Ruben | last9=Belfiore | first9=Andrea | last10=Israel | first10=Gianluca | last11=Haberl | first11=Frank | last12=D'Agostino | first12=Daniele | date=2017 | title=Discovery of periodic dips in the brightest hard X-ray source of M31 with EXTraS | journal=The Astrophysical Journal Letters | volume=851 | issue=2 | pages=L27 | bibcode=2017ApJ...851L..27M | doi=10.3847/2041-8213/aa9b2e | arxiv=1711.05540 | s2cid=119266242 | doi-access=free }}</ref>
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<ref name="GalaxyMass">"The median values of the Milky Way and Andromeda masses are M<sub>G</sub> = {{val|0.8|0.4|0.3|e=12|u=solar mass}} and M<sub>A</sub> = {{val|1.5|0.5|0.4|e=12|u=solar mass}} at a 68% level" {{cite journal | first1=Jorge |last1=Peñarrubia | first2=Yin-Zhe |last2=Ma | first3=Matthew G. |last3=Walker | first4=Alan W. |last4=McConnachie | title=A dynamical model of the local cosmic expansion | journal=Monthly Notices of the Royal Astronomical Society | volume=433 | issue=3 | date=29 July 2014 | pages=2204–2222 | bibcode= 2014MNRAS.443.2204P | doi=10.1093/mnras/stu879|doi-access=free |arxiv = 1405.0306 |s2cid=119295582}}, but compare "[we estimate] the virial mass and radius of the galaxy to be {{cvt|0.8|+/-|0.1|e12solar mass|kg|lk=on}}" {{cite journal | first1 = Prajwal R. |last1=Kafle | first2 = Sanjib |last2=Sharma | first3 = Geraint F. |last3=Lewis | display-authors=3 | first4 = Aaron S. G. |last4=Robotham | first5 = Simon P. | last5=Driver | title = The Need for Speed: Escape velocity and dynamical mass measurements of the Andromeda Galaxy | journal = Monthly Notices of the Royal Astronomical Society | volume = 475 | issue = 3 | date = 1 February 2018 | pages=4043–4054 | bibcode = 2018MNRAS.475.4043K | issn=0035-8711 | doi = 10.1093/mnras/sty082|doi-access=free |arxiv = 1801.03949 |s2cid=54039546}}</ref>
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<ref name="nake">{{cite news |title=Two naked-eye galaxies above the VLT |url=http://www.eso.org/public/images/potw1342a/ |access-date=22 October 2013 |newspaper=ESO Picture of the Week}}</ref>
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