Lihat sumber Galaksi Andromeda

{{Infobox galaxy
| name               = Galaksi Andromeda 
|image=[[Berkas:M31 09-01-2011.jpg|300px]]
| epoch = [[Epoch (astronomy)#Julian years and J2000|J2000]]
| pronounce = {{IPAc-en|æ|n|ˈ|d|r|ɒ|m|ᵻ|d|ə}}
| type = SA(s)b<ref name="ned" />
| mass = ~0,8-1,5{{e|12}}<ref name="Kafle2018">{{cite journal
    | first = Prajwal R. |last=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|arxiv = 1801.03949 }}</ref>
| size = ~220 Kly (diameter)<ref name="Chapman et al 2006" />
| stars = ~1 triliun (10<sup>12</sup>)<!-- exponential value to disambiguate "trillion" --><ref name="trillion-stars" />
| age = 5 hingga 9 miliar tahun<ref name="Moskvitch 2010">{{cite news 
| last = Moskvitch
| first = Katia
| date = 25 November 2010
| title = Andromeda 'born in a collision'
| url = http://www.bbc.co.uk/news/science-environment-11833356
| publisher = [[BBC News]]
| accessdate = 25 November 2010
| archiveurl = https://web.archive.org/web/20101126042510/http://www.bbc.co.uk/news/science-environment-11833356
| archivedate = 26 November 2010
| deadurl = no
}}
</ref>
| ra = {{RA|00|42|44.3}}<ref name="ned" />
| dec = {{DEC|+41|16|9}}<ref name="ned" />
| dist_ly = 2,54 ± 0,11 [[light-year|Mly]] <br> (778 ± 33 [[parsec|kpc]])<ref name="Karachentsevetal2006" /><ref name="McConnachieetal2005" />{{efn|name=avg dist}}
| z = z = −0,001001  
| h_radial_v = −301 ± 1 km/s<ref name="Karachentsevetal2006" />
| appmag_v = 3,44<ref name="SIMBAD-M31" /><ref name="GAXEL" />
| size_v = 3,167° × 1°<ref name="ned" />
| constellation name = [[Andromeda (constellation)|Andromeda]]
| absmag_v = −21,5{{efn|name=blue mag}}<ref name="Ribas2005" />
| names = [[Objek Messier|M]]31, [[New General Catalogue|NGC]] 224, UGC 454, PGC 2557, [[Second Cambridge Catalogue of Radio Sources|2C]] 56 (Core),<ref name="ned" /> CGCG 535-17, MCG +07-02-016, IRAS 00400+4059, 2MASX J00424433+4116074, GC 116, h 50, Bode 3, Flamsteed 58, Hevelius 32, Ha 3.3, IRC +40013
}}
'''Galaksi Andromeda''' (nama lain, '''Messier 31''' dan '''NGC 224''') adalah sebuah [[galaksi spiral]] yang berjarak kira-kira 2,5 juta [[tahun cahaya]] dari bumi. Galaksi ini merupakan salah satu [[galaksi]] di luar galaksi [[Bima Sakti]] yang dapat dilihat dengan mata telanjang pada malam yang cerah, tanpa [[bulan]], dan tanpa polusi [[cahaya]].

Strukturnya mirip dengan galaksi Bima Sakti yaitu berbentuk [[spiral]]. Jaraknya sekitar 2,5 juta [[tahun cahaya]]. Letaknya di langit adalah di belahan langit [[utara]], sekitar 41 derajat di sebelah utara khatulistiwa langit. Galaksi ini dapat diamati di bulan [[September]], [[Oktober]], dan [[November]].<ref>{{Cite web|url=https://earthsky.org/clusters-nebulae-galaxies/andromeda-galaxy-closest-spiral-to-milky-way|title=Andromeda galaxy, closest large spiral {{!}} EarthSky.org|website=earthsky.org|language=en-US|access-date=2020-08-02|archive-date=2023-07-25|archive-url=https://web.archive.org/web/20230725110709/https://earthsky.org/clusters-nebulae-galaxies/andromeda-galaxy-closest-spiral-to-milky-way/|dead-url=no}}</ref>

Dengan mata telanjang, galaksi ini tampak seperti [[kabut]] tipis kecil di langit utara. Namun, jika diamati dengan [[teropong]] yang dapat menampakkan bintang-bintang redup di tepian galaksi Andromeda, ukurannya bisa lebih dari 7 kali diameter sudut bulan. Galaksi ini berisi sekitar 1 triliun [[bintang]] dan bergerak mendekati Bima Sakti dengan kecepatan sekitar 300&nbsp;km/detik.

== Struktur ==
Morfologi galaksi Andromeda diklasifikasikan sebagai SA(s)b dalam [[Klasifikasi morfologi galaksi#Sistem klasifikasi De Vaucouleurs|Klasifikasi De Vaucouleurs]].<ref name="ned">{{Cite web|url=http://ned.ipac.caltech.edu/cgi-bin/objsearch?objname=M+031&extend=no&hconst=73&omegam=0.27&omegav=0.73&corr_z=1&out_csys=Equatorial&out_equinox=J2000.0&obj_sort=RA+or+Longitude&of=pre_text&zv_breaker=30000.0&list_limit=5&img_stamp=YES#BasicData_0|title=Your NED Search Results|website=ned.ipac.caltech.edu|access-date=2020-03-16|archive-date=2018-08-09|archive-url=https://web.archive.org/web/20180809115121/http://ned.ipac.caltech.edu/cgi-bin/objsearch?objname=M+031&extend=no&hconst=73&omegam=0.27&omegav=0.73&corr_z=1&out_csys=Equatorial&out_equinox=J2000.0&obj_sort=RA+or+Longitude&of=pre_text&zv_breaker=30000.0&list_limit=5&img_stamp=YES#BasicData_0|dead-url=no}}</ref> Namun, pada tahun 2007, data terbaru dari [[2MASS]] menunjukkan bahwa morfologi galaksi Andromeda sebenarnya adalah [[Galaksi spiral|galaksi spiral berbatang]].<ref>{{Cite journal|last=Beaton|first=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|date=2007-04|title=Unveiling the Boxy Bulge and Bar of the Andromeda Spiral Galaxy|url=https://ui.adsabs.harvard.edu/abs/2007ApJ...658L..91B/abstract|journal=ApJL|language=en|volume=658|issue=2|pages=L91–L94|doi=10.1086/514333|issn=0004-637X|access-date=2020-03-17|archive-date=2022-11-23|archive-url=https://web.archive.org/web/20221123024752/https://ui.adsabs.harvard.edu/abs/2007ApJ...658L..91B/abstract|dead-url=no}}</ref>

Tahun 1998, [[European Space Agency|Badan Luar Angkasa Eropa]] mengumumkan bahwa Andromeda memiliki struktur cincin bersamaan dengan struktur spiralnya. Struktur ini tidak bisa terlihat dengan mudah karena terdiri dari debu yang dingin sehingga dibutuhkan [[teleskop]] [[Inframerah]] untuk melihatnya.<ref>{{Cite web|url=https://sci.esa.int/web/iso/-/12748-iso-unveils-the-hidden-rings-of-andromeda|title=ESA Science & Technology - ISO unveils the hidden rings of Andromeda|website=sci.esa.int|access-date=2020-03-16|archive-date=2023-03-31|archive-url=https://web.archive.org/web/20230331103712/https://sci.esa.int/web/iso/-/12748-iso-unveils-the-hidden-rings-of-andromeda|dead-url=no}}</ref>

Selanjutnya, sebuah studi lain memperlihatkan bagaimana struktur spiralnya memanjang dari [[Pusat Galaksi|inti galaksi]] melampaui cincin-cincin tadi, namun strukturnya tidak berkelanjutan dan tersegmentasi.<ref>{{Cite journal|last=Gordon|first=K. D.|last2=Bailin|first2=J.|last3=Engelbracht|first3=C. W.|last4=Rieke|first4=G. H.|last5=Misselt|first5=K. A.|last6=Latter|first6=W. B.|last7=Young|first7=E. T.|last8=Ashby|first8=M. L. N.|last9=Barmby|first9=P.|date=2006-02-03|title=Spitzer MIPS Infrared Imaging of M31: Further Evidence for a Spiral-Ring Composite Structure|url=https://iopscience.iop.org/article/10.1086/501046/meta|journal=The Astrophysical Journal Letters|language=en|volume=638|issue=2|pages=L87|doi=10.1086/501046|issn=1538-4357|access-date=2020-03-17|archive-date=2022-03-08|archive-url=https://web.archive.org/web/20220308192504/https://iopscience.iop.org/article/10.1086/501046/meta|dead-url=no}}</ref>

Kebanyakan para astronom berpikir kalau galaksi Andromeda dengan [[Galaksi Bima Sakti|Galaksi Bimasakti]] agak berbeda selama beberapa dekade terakhir. Hingga pada tahun 2005, sekelompok astronom menggunakan [[Observatorium Keck]] untuk meneliti halo bintangnya. Hasilnya menunjukkan bahwa [[metalisitas]] halo bintang Andromeda sangatlah miskin.[[Berkas:Three Faces of Andromeda.jpg|jmpl|331x331px|Pada tahun 2004, [[Teleskop luar angkasa Spitzer]] mengungkapkan struktur Andromeda yang menakjubkan untuk meneliti lebih lanjut dari apa yang diisyaratkan dari penampakannya]]Hal ini cukup mengejutkan, karena selama ini perbedaan antara mereka dianggap terletak di metalisitas halo bintangnya. Ini artinya jika mereka sama-sama miskin metalisitas, maka setidaknya mereka pernah berevolusi sama-sama.<ref>{{Cite web|url=http://pr.caltech.edu/media/Press_Releases/PR12801.html|title=Caltech Press Release, 2/27/2006, Dr. Scott Chapman|date=2006-05-09|website=web.archive.org|access-date=2020-03-16|archive-date=2006-05-09|archive-url=https://web.archive.org/web/20060509072644/http://pr.caltech.edu/media/Press_Releases/PR12801.html|dead-url=unfit}}</ref>

== Inti ==
[[Berkas:M31 Core in X-rays.jpg|al=|kiri|jmpl|212x212px|Inti Andromeda dalam citra [[sinar-X]] [[Observatorium Chandra]]. Cahaya biru menandakan [[lubang hitam supermasif]]]]
Andromeda memiliki inti yang sangat kompak dan padat sehingga sulit untuk diketahui strukturnya dari [[bumi]]. Pada bulan Juni 1991, [[Teleskop luar angkasa Hubble|Teleskop Hubble]] diarahkan untuk meneliti inti Andromeda. Hasil observasi tersebut menunjukkan terdapat dua konsentrasi pada intinya yang terpisah sejauh 0.49" (4.9 [[tahun cahaya]]).

Konsentrasi yang terang dinamai P1, sementara konsentrasi yang redup dinamai P2. Konsentrasi P2 jatuh di pusat sebenarnya galaksi ini, dan memiliki lubang hitam yang memiliki massa kurang lebih 1–5 × 10<sup>7</sup> <var>M</var><sub>☉</sub><ref>{{Cite journal|last=Lauer|first=T. R.|last2=Faber|first2=S. M.|last3=Groth|first3=E. J.|last4=Shaya|first4=E. J.|last5=Campbell|first5=B.|last6=Code|first6=A.|last7=Currie|first7=D. G.|last8=Baum|first8=W. A.|last9=Ewald|first9=S. P.|date=1993-10|title=Planetary Camera Observations of the Double Nucleus of M31|url=https://ui.adsabs.harvard.edu/abs/1993AJ....106.1436L/abstract|journal=AJ|language=en|volume=106|pages=1436|doi=10.1086/116737|issn=0004-6256|access-date=2020-03-17|archive-date=2023-07-16|archive-url=https://web.archive.org/web/20230716040326/https://ui.adsabs.harvard.edu/abs/1993AJ....106.1436L/abstract|dead-url=no}}</ref>

Awal penjelasan penyebab P1 lebih terang adalah sisa-sisa dari galaksi kecil yang 'dimakan' oleh galaksi Andromeda (kemudian muncul penjelasan inti yang sebenarnya satu yang tertutupi debu).<ref>{{Cite web|url=http://www.aip.org/pnu/1993/split/pnu138-2.htm|title=Physics News Update Number 138 - THE ANDROMEDA GALAXY HAS A DOUBLE NUCLEUS|date=2009-08-15|website=web.archive.org|access-date=2020-03-17|archive-date=2009-08-15|archive-url=https://web.archive.org/web/20090815062838/http://www.aip.org/pnu/1993/split/pnu138-2.htm|dead-url=unfit}}</ref> Tapi penjelasan ini tidak lagi kuat karena konsentrasi ini akan memiliki paruh hidup yang pendek sebagai akibat dari gangguan pasang surut [[lubang hitam]].

Meskipun masalah ini terselesaikan separuhnya bila P1 ini memiliki lubang hitam sendiri yang menstabilkan dirinya, tetapi distribusi pergerakan bintangnya menunjukkan tidak ada indikasi [[lubang hitam]] di P1.{{Infobox astronomical event|epoch=[[J2000]]|constellation=[[Andromeda]]|distance=2.2 juta [[tahun cahaya]]|name=PA-99-N2|image=|names=|redshift=|start_time=1999|event_type=[[lensa gravitasi|mikrolensa gravitasi]]|commons=|dec=+41° 28′ 44.6″|fetchwikidata=|ra=00j 44m 20.89d}}

== Dugaan eksoplanet ==
'''PA-99-N2''' adalah sebuah peristiwa [[Lensa gravitasi|mikrolensa gravitasi]] yang terjadi di galaksi Andromeda pada tahun 1999. Salah satu penjelasannya adalah sebuah bintang (yang memiliki massa setengah dari [[matahari]]) melensakan sebuah [[raksasa merah]].

Peristiwa ini mengungkapkan adanya sebuah planet mirip [[Jupiter]] pada raksasa merah tersebut.<ref>{{Cite web|url=http://exoplanet.eu/catalog/pa-99-n2_b/|title=The Extrasolar Planet Encyclopaedia — PA-99-N2 b|website=exoplanet.eu|access-date=2020-03-17|archive-date=2021-01-24|archive-url=https://web.archive.org/web/20210124062722/http://exoplanet.eu/catalog/pa-99-n2_b/|dead-url=no}}</ref> Jika ini terkonfirmasi, maka planetnya akan menjadi planet pertama yang ditemukan di luar [[Galaksi Bimasakti]]. Namun, studi selanjutnya menunjukkan terdapat anomali pada peristiwa ini.<ref>{{Cite journal|last=An|first=Jin H.|last2=Evans|first2=N. W.|last3=Kerins|first3=E.|last4=Baillon|first4=P.|last5=Calchi Novati|first5=S.|last6=Carr|first6=B. J.|last7=Creze|first7=M.|last8=Giraud‐Heraud|first8=Y.|last9=Gould|first9=A.|date=2004-02|title=The Anomaly in the Candidate Microlensing Event PA‐99‐N2|url=https://iopscience.iop.org/article/10.1086/380820|journal=The Astrophysical Journal|language=en|volume=601|issue=2|pages=845–857|doi=10.1086/380820|issn=0004-637X|access-date=2020-03-17|archive-date=2023-02-10|archive-url=https://web.archive.org/web/20230210131909/https://iopscience.iop.org/article/10.1086/380820|dead-url=no}}</ref>

== Referensi ==
{{reflist|refs=
<ref name="Karachentsevetal2006">{{cite journal | last1 = Karachentsev | first1 = Igor D. | last2 = Kashibadze | first2 = Olga G. | date = 2006 | title = Masses of the Local Group and of the M81 group estimated from distortions in the local velocity field | journal = [[Astrophysics (journal)|Astrophysics]] | volume = 49 | issue = 1 | pages = 3–18 | bibcode = 2006Ap.....49....3K | doi = 10.1007/s10511-006-0002-6 | s2cid = 120973010}}</ref>
<ref name="McConnachieetal2005">{{cite journal | last1 = McConnachie | first1 = Alan W. | last2 = Irwin | first2 = Michael J. | last3 = Ferguson | first3 = Annette M. N. | display-authors=3 | last4 = Ibata | first4 = Rodrigo A. | last5 = Lewis | first5 = Geraint F. | last6 = Tanvir | first6 = Nial R. | date = 2005 | title = Distances and metallicities for 17 Local Group galaxies | journal = [[Monthly Notices of the Royal Astronomical Society]] | volume = 356 | issue = 4 | pages = 979–997 | bibcode = 2005MNRAS.356..979M | arxiv = astro-ph/0410489 | doi = 10.1111/j.1365-2966.2004.08514.x}}</ref>
<ref name="SIMBAD-M31">{{cite web | title = M 31 | url = http://simbad.u-strasbg.fr/simbad/sim-id?Ident=m31 | access-date = 30 September 2018 | archive-date = 2014-05-19 | archive-url = https://web.archive.org/web/20140519223154/http://simbad.u-strasbg.fr/simbad/sim-id?Ident=M31 | dead-url = no }}</ref>
<ref name="GAXEL">{{cite journal | date = 2007 | title = The GALEX Ultraviolet Atlas of Nearby Galaxies | url = https://archive.org/details/sim_astrophysical-journal_2007-12_173_2/page/185 | journal = [[Astrophysical Journal]] | volume = 173 | issue = 2 | pages = 185–255 | arxiv = astro-ph/0606440 | bibcode = 2007ApJS..173..185G | doi = 10.1086/516636 | last1 = Gil de Paz | first1 = Armando | last2 = Boissier | first2 = Samuel | last3 = Madore | first3 = Barry F. | display-authors=3 | last4 = Seibert | first4 = Mark | last5 = Joe | first5 = Young H. | last6 = Boselli | first6 = Alessandro | last7 = Wyder | first7 = Ted K. | last8=Thilker |first8=David A. | last9=Bianchi |first9=Luciana | last10 = Rey | first10 = Soo‐Chang | last11 = Rich | first11 = Robert Michael | last12 = Barlow | first12 = Tom A. | last13 = Conrow | first13 = Tim | last14 = Forster | first14 = Karl | last15 = Friedman | first15 = Peter G. | last16 = Martin | first16 = D. Christopher | last17 = Morrissey | first17 = Patrick | last18 = Neff | first18 = Susan G. | last19 = Schiminovich | first19 = David | last20 = Small | first20 = Todd | last21 = Donas | first21 = Jose | last22 = Heckman | first22 = Timothy M. | last23 = Lee | first23 = Young‐Wook | last24 = Milliard | first24 = Bruno | last25 = Szalay | first25 = Alex S. | last26 = Yi | first26 = Sukyoung | s2cid = 119085482}}</ref>
<ref name="Ribas2005">{{cite journal | last1 = Ribas | first1 = Ignasi | last2 = Jordi | first2 = Carme | last3 = Vilardell | first3 = Francesc | display-authors=3 | last4 = Fitzpatrick | first4 = Edward L. | last5 = Hilditch | first5 = Ron W. | last6 = Guinan | first6 = Edward F. | date = 2005 | title = First Determination of the Distance and Fundamental Properties of an Eclipsing Binary in the Andromeda Galaxy | journal = [[Astrophysical Journal Letters]] | volume = 635 | issue = 1 | pages = L37–L40 | bibcode = 2005ApJ...635L..37R | arxiv = astro-ph/0511045 | doi = 10.1086/499161 | s2cid = 119522151}}</ref>
<ref name="Chapman et al 2006">{{cite journal | last1 = Chapman | first1 = Scott C. | last2 = Ibata | first2 = Rodrigo A. | last3 = Lewis | first3 = Geraint F. | display-authors=3 | last4 = Ferguson | first4 = Annette M. N. | last5 = Irwin | first5 = Michael J. | last6 = McConnachie | first6 = Alan W. | last7 = Tanvir | first7 = Nial R. | date = 2006 | title = A kinematically selected, metal-poor spheroid in the outskirts of M31 | journal = [[Astrophysical Journal]] | volume = 653 | issue = 1 | pages = 255–266 | arxiv = astro-ph/0602604 | doi = 10.1086/508599 | bibcode = 2006ApJ...653..255C | s2cid = 14774482}} Also see the press release, {{cite press release | publisher = [[Caltech|Caltech Media Relations]] | date = 27 February 2006 | title = Andromeda's Stellar Halo Shows Galaxy's Origin to Be Similar to That of Milky Way | url = http://pr.caltech.edu/media/Press_Releases/PR12801.html | access-date = 24 May 2006 | archive-url = https://web.archive.org/web/20060509072644/http://pr.caltech.edu/media/Press_Releases/PR12801.html | archive-date = 9 May 2006 | url-status = dead | df = dmy-all }} {{Cite web |url=http://pr.caltech.edu/media/Press_Releases/PR12801.html |title=Salinan arsip |access-date=2020-03-17 |archive-date=2006-05-09 |archive-url=https://web.archive.org/web/20060509072644/http://pr.caltech.edu/media/Press_Releases/PR12801.html |dead-url=unfit }}</ref>
<ref name="trillion-stars">{{cite magazine | last = Young | first = Kelly | date = 6 June 2006 | title = The Andromeda Galaxy hosts a trillion stars | url = https://www.newscientist.com/article/dn9282-andromeda-galaxy-hosts-a-trillion-stars.html | magazine = [[New Scientist]] | access-date = 6 October 2014}}</ref>
}}

== Pranala luar ==

* [http://blackholes.stardate.org/directory/factsheet.php?p=M31 StarDate: M31 Fact Sheet] {{Webarchive|url=https://web.archive.org/web/20110722021459/http://blackholes.stardate.org/directory/factsheet.php?p=M31 |date=2011-07-22 }}
* [http://simbad.u-strasbg.fr/sim-id.pl?Ident=M+31 Simbad data on M31] {{Webarchive|url=https://web.archive.org/web/20001206111400/http://simbad.u-strasbg.fr/sim-id.pl?Ident=M+31 |date=2000-12-06 }}
* [http://www.seds.org/messier/m/m031.html Messier 31, SEDS Messier pages] {{Webarchive|url=https://web.archive.org/web/20061205045436/http://seds.org/messier/m/m031.html |date=2006-12-05 }}
* [[Astronomy Picture of the Day]]
** [http://antwrp.gsfc.nasa.gov/apod/ap981017.html A Giant Globular Cluster in M31] {{Webarchive|url=https://web.archive.org/web/20041204105113/http://antwrp.gsfc.nasa.gov/apod/ap981017.html |date=2004-12-04 }} 1998 October 17.
** [http://antwrp.gsfc.nasa.gov/apod/ap040718.html M31: The Andromeda Galaxy] {{Webarchive|url=https://web.archive.org/web/20050303012350/http://antwrp.gsfc.nasa.gov/apod/ap040718.html |date=2005-03-03 }} 2004 July 18.
** [http://antwrp.gsfc.nasa.gov/apod/ap051222.html Andromeda Island Universe] {{Webarchive|url=https://web.archive.org/web/20051228024604/http://antwrp.gsfc.nasa.gov/apod/ap051222.html |date=2005-12-28 }} 2005 December 22.
** [http://apod.nasa.gov/apod/ap100109.html Andromeda Island Universe] {{Webarchive|url=https://web.archive.org/web/20100114015405/http://apod.nasa.gov/apod/ap100109.html |date=2010-01-14 }} 2010 January 9.
** [http://antwrp.gsfc.nasa.gov/apod/ap100219.html WISE Infrared Andromeda] {{Webarchive|url=https://web.archive.org/web/20100222201457/http://antwrp.gsfc.nasa.gov/apod/ap100219.html |date=2010-02-22 }} 2010 February 19
* [http://www.daviddarling.info/encyclopedia/A/Andromeda.html Andromeda Galaxy at The Encyclopedia of Astrobiology, Astronomy, & Spaceflight] {{Webarchive|url=https://web.archive.org/web/20101115160115/http://daviddarling.info/encyclopedia/A/Andromeda.html |date=2010-11-15 }}
* [http://www.nightskyinfo.com/archive/m31_galaxy M31, the Andromeda Galaxy] {{Webarchive|url=https://web.archive.org/web/20101229012601/http://www.nightskyinfo.com/archive/m31_galaxy/ |date=2010-12-29 }} at NightSkyInfo.com
* {{cite news
 |last = Than
 |first = Ker
 |date = January 23, 2006
 |title = Strange Setup: Andromeda's Satellite Galaxies All Lined Up
 |publisher = Space.com
 |url = http://space.com/scienceastronomy/060123_andromeda_plane.html
 |access-date = 2014-06-20
 |archive-date = 2010-08-08
 |archive-url = https://web.archive.org/web/20100808175402/http://www.space.com/scienceastronomy/060123_andromeda_plane.html
 |dead-url = no
 }}
* [http://hubblesite.org/newscenter/archive/releases/2005/26/full/ Hubble Finds Mysterious Disk of Blue Stars Around Black Hole] {{Webarchive|url=https://web.archive.org/web/20100731011456/http://hubblesite.org/newscenter/archive/releases/2005/26/full/ |date=2010-07-31 }} Hubble observations (Sep 20 2005) put the mass of the Andromeda core black hole at 140 million solar masses
* [http://cbat.eps.harvard.edu/CBAT_M31.html M31 (Apparent) Novae Page] {{Webarchive|url=https://web.archive.org/web/20110719204305/http://cbat.eps.harvard.edu/CBAT_M31.html |date=2011-07-19 }} (IAU)
* {{WikiSky|messier 31}}

{{commonscat|Andromeda Galaxy}}
{{Galaksi Andromeda}}
{{Obyek Messier}}
{{galaksi}}
{{Sky|00|42.44|30|+|41|16|10|2360000}}

[[Kategori:Rasi bintang Andromeda]]
[[Kategori:Galaksi]]
[[Kategori:Objek Messier|031]]