View source for Messier 82

{{Short description|Galaxy in the constellation Ursa Major}}
{{Use dmy dates|date=September 2019}}
{{Infobox Galaxy
| name = [[Messier object|Messier]] 82
| image = M82 HST ACS 2006-14-a-large web.jpg
| caption = A mosaic image taken by the [[Hubble Space Telescope]] of Messier 82, combining exposures taken with four colored filters that capture starlight from visible and infrared wavelengths as well as the light from the glowing hydrogen filaments
| credit = 
| epoch = [[J2000]]
| type = I0<ref name="ned">
{{cite web
 | website = NASA/IPAC Extragalactic Database
 | title = Results for object NGC 3034
 | url = http://ned.ipac.caltech.edu/cgi-bin/objsearch?objname=m82&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
 | access-date = 27 October 2006 }}</ref>
| ra = {{RA|09|55|52.9200}}<ref name="ned" />
| dec = {{DEC|+69|40|46.140}}<ref name="ned" />
| z = {{val|0.000897|0.000007}}{{r|ned}}
| dist_ly = 11.4–12.4 [[light-year|Mly]] (3.5–3.8 [[parsec|Mpc]])<ref name="Karachentsevetal2006" />
| size = {{convert|12.52|kpc|ly|sigfig=3|abbr=off|lk=on}}<br />(diameter; [[Galaxy#Isophotal diameter|25.0 mag/arcsec<sup>2</sup> B-band isophote]])<ref name="ned" /><ref name=RC3>{{cite book | bibcode=1991rc3..book.....D | year=1991 | title=Third Reference Catalogue of Bright Galaxies | last1=De Vaucouleurs | first1=Gerard | last2=De Vaucouleurs | first2=Antoinette | last3=Corwin | first3=Herold G. | last4=Buta | first4=Ronald J. | last5=Paturel | first5=Georges | last6=Fouque | first6=Pascal }}</ref>
| h_radial_v = {{val|269|2|u=km/s}}<ref name="ned" />
| appmag_v = 8.41<ref name="SIMBAD-M82">{{cite simbad | title=M 82 | access-date=2018-12-14 }}</ref><ref name=GAXEL>
{{cite journal
 |last=Armando |first=Gil de Paz
 |year=2007
 |author2=Boissier |author3=Madore |author4=Seibert |author5=Boselli |display-authors= etal 
 |title=The GALEX Ultraviolet Atlas of Nearby Galaxies
 |journal=[[Astrophysical Journal Supplement]]
 |volume=173
 |issue=2 |pages=185–255
 |arxiv=astro-ph/0606440
 |doi=10.1086/516636
|bibcode=2007ApJS..173..185G
|s2cid=119085482
 }}</ref>
| size_v = {{Val|11.2|×|4.3|u=arcminute}}<ref name="ned" />
| constellation name = [[Ursa Major]]
| notes = Edge-on starburst galaxy
| names = {{odlist | NGC= 3034 | UGC= 5322 | Arp= 337 | name= Cigar Galaxy | PGC= 28655 | name2= [[Third Cambridge Catalogue of Radio Sources|3C]] 231 | CGCG= 333-008 | MCG= +12-10-011 | IRAS= 09517+6954}}<ref name="ned" />
}}
{{multiple images
| align             = right
| direction         = vertical
| header            = M82 Galaxy
| width             = 175
| footer            = 
| image1            = PIA23010-M82-CigarGalaxy-20190305.jpg
| caption1          = M82 magnetic field
| width1            = 
| image2            = M82 Chandra HST Spitzer.jpg
| caption2          = Composite image – [[Hubble Space Telescope|HST]] (vis); [[Spitzer Space Telescope|Spitzer]] (ir); [[Chandra X-ray Observatory|Chandra]] (x-ray)
| width2            = 
| image3            = M82(2).jpg
| caption3          = Chandra X-ray observatory image of the galaxy
| width3            = 
| image4            = M82 (NIRCam image - longer wavelengths) (weic2410b).jpg
| caption4          = [[James Webb Space Telescope|James Webb]] [[NIRCam]] image of the center of M82
| width4            = 
| image5            = Hubble views new supernova in Messier 82.jpg
| caption5          = [[Hubble Space Telescope|Hubble]] views new supernova in Messier 82<ref>{{cite news|title=Hubble views new supernova in Messier 82|url=http://www.spacetelescope.org/images/potw1409a/|access-date=12 March 2014|newspaper=ESA / HUBBLE}}</ref>
| width5            = 
| image6            = M 82 supernova.jpg
| caption6          = M82 – December 2013; supernova – January 2014 (bottom)
| width6            = 
| image7            = M82 Bin1 No Logo Resample.jpg
| caption7          = Messier 82 photographed by amateur astrophotographer Radu Marinescu using a 10" Newtonian telescope, with a high emphasis on the Hydrogen-alpha star-burst areas.
}}
'''Messier 82''' (also known as '''NGC 3034''', '''Cigar Galaxy''' or '''M82''') is a [[starburst galaxy]] approximately 12 million [[light-year]]s away in the [[constellation]] [[Ursa Major]]. It is the second-largest member of the [[M81 Group]], with the [[Galaxy#Isophotal diameter|D<sub>25</sub> isophotal diameter]] of {{convert|12.52|kpc|ly|sigfig=3|abbr=off|lk=on}}.<ref name="ned" /><ref name=RC3 /> It is about five times [[Luminosity#Astronomy|more luminous]] than the [[Milky Way]] and its central region is about one hundred times more luminous.<ref name="Barkeretal2008" /> The [[Starburst region|starburst activity]] is thought to have been triggered by interaction with neighboring galaxy [[Messier 81|M81]]. As one of the closest starburst galaxies to Earth, M82 is the prototypical example of this galaxy type.<ref name="Barkeretal2008">
{{cite journal
 | last1 = Barker | first1 = S.
 | last2 = de Grijs | first2 = R.
 | last3 = Cerviño | first3 = M.
 | date = 2008
 | title = Star cluster versus field star formation in the nucleus of the prototype starburst galaxy M 82
 | journal=[[Astronomy and Astrophysics]]
 | volume = 484 | issue = 3 | pages = 711–720
 | bibcode = 2008A&A...484..711B
 | doi = 10.1051/0004-6361:200809653
|arxiv = 0804.1913 | s2cid = 18885080
 }}</ref>{{efn|name=Starburst|The irregular galaxy [[IC 10]] in the [[Local Group]] is sometimes classified as a starburst galaxy, and hence is the closest such galaxy to Earth.}} [[SN 2014J]], a [[Type Ia supernova]], was discovered in the galaxy on 21 January 2014.<ref name="astronomerstelegram.org">{{cite web|url=http://www.astronomerstelegram.org/?read=5786|title=ATel #5786: Classification of Supernova in M82 as a young, reddened Type Ia Supernova|website=ATel|access-date=14 April 2018}}</ref><ref name="Huffington Post">{{Cite web |date=22 January 2014 |title=Sudden Supernova in M82 Galaxy Rips Apart The Night Sky (A Bit) |url=http://www.huffingtonpost.co.uk/2014/01/22/m82-supernova_n_4644356.html |website=[[Huffington Post]]}}</ref><ref name="slate.com">{{cite journal|url=http://www.slate.com/blogs/bad_astronomy/2014/01/22/kaboom_nearby_galaxy_m82_hosts_a_new_supernova.html|title=KABOOM! Nearby Galaxy M82 Hosts a New Supernova!|first=Phil|last=Plait|date=22 January 2014|journal=Slate}}</ref> In 2014, in studying M82, scientists discovered the brightest [[pulsar]] yet known, designated [[M82 X-2]].<ref>{{Cite web |last=Tillman |first=Nola Taylor |date=8 October 2014 |title=Shockingly Bright Dead Star with a Pulse Is an X-ray Powerhouse |url=http://www.space.com/27385-pulsar-discovery-superbright-xray-beacon.html |publisher=[[Space.com]]}}</ref><ref>{{Cite web |last=Chu |first=Jennifer |date=8 October 2014 |title=Researchers detect brightest pulsar ever recorded |url=http://newsoffice.mit.edu/2014/brightest-pulsar-detected-1008 |publisher=[[Massachusetts Institute of Technology]]}}</ref><ref>{{cite web|title=NASA's NuSTAR Telescope Discovers Shockingly Bright Dead Star|url=http://www.nasa.gov/press/2014/october/nasa-s-nustar-telescope-discovers-shockingly-bright-dead-star/#.VDgaKPldVqs|publisher=[[NASA]]|date=8 October 2014}}</ref>

In November 2023, a [[gamma-ray burst]] was observed in M82, which was determined to have come from a [[magnetar]], the first such event detected outside the [[Milky Way]] (and only the fourth such event ever detected).<ref>{{cite journal|last1=Mereghetti|first1=Sandro|last2=Rigoselli|first2=Michela|last3=Salvaterra|first3=Ruben|last4=Pacholski|first4=Dominik Patryk|last5=Rodi|first5=James Craig|last6=Gotz|first6=Diego|last7=Arrigoni|first7=Edoardo|last8=D'Avanzo|first8=Paolo|last9=Adami|first9=Christophe|last10=Bazzano|first10=Angela|last11=Bozzo|first11=Enrico|last12=Brivio|first12=Riccardo|last13=Campana|first13=Sergio|last14=Cappellaro|first14=Enrico|last15=Chenevez|first15=Jerome|last16=De Luise|first16=Fiore|last17=Ducci|first17=Lorenzo|last18=Esposito|first18=Paolo|last19=Ferrigno|first19=Carlo|last20=Ferro|first20=Matteo|last21=Israel|first21=Gian Luca|last22=Le Floc'h|first22=Emeric|last23=Martin-Carrillo|first23=Antonio|last24=Onori|first24=Francesca|last25=Rea|first25=Nanda|last26=Reguitti|first26=Andrea|last27=Savchenko|first27=Volodymyr|last28=Souami|first28=Damya|last29=Tartaglia|first29=Leonardo|last30=Thuillot|first30=William|last31=Tiengo|first31=Andrea|last32=Tomasella|first32=Lina|last33=Topinka|first33=Martin|last34=Turpin|first34=Damien|last35=Ubertini|first35=Pietro|date=10 March 2024|title=A magnetar giant flare in the nearby starburst galaxy M82|journal=Astrophysics|volume=629 |issue=2|pages=58–61 |doi=10.1038/s41586-024-07285-4 |pmid=38658757 |arxiv=2312.14645|bibcode=2024Natur.629...58M }}</ref><ref>{{cite news|last=Smith|first=Kiona|title=A Dead Star in a Nearby Galaxy Just Did Something Wild|url=https://www.inverse.com/science/magnetar-galaxy-m82-dead-star-gamma-ray-burst|website=Inverse|date=25 April 2024|accessdate=26 April 2024}}</ref>

==Discovery==
M82, with [[Messier 81|M81]], was discovered by [[Johann Elert Bode]] in 1774; he described it as a "nebulous patch", this one about {{frac|3|4}} degree away from the other, "very pale and of elongated shape". In 1779, [[Pierre Méchain]] independently rediscovered both objects and reported them to [[Charles Messier]], who added them to his catalog.<ref name="seds">{{Cite web|title= Messier 82 |work=SEDS |url= http://messier.seds.org/m/m082.html}}</ref>

==Structure==
M82 was believed to be an [[irregular galaxy]].  In 2005, however, two symmetric [[spiral arm]]s were discovered in [[near-infrared]] (NIR) images of M82.  The arms were detected by subtracting an [[axisymmetric]] exponential disk from the NIR images.  Even though the arms were detected in NIR images, they are bluer than the disk. The arms had been missed due to M82's high disk [[surface brightness]], the nearly edge-on view of this galaxy (~80°),<ref name="Barkeretal2008" /> and obscuration by a complex network of dusty filaments in its optical images. These arms emanate from the ends of the NIR [[Barred spiral galaxy|bar]] and can be followed for the length of three [[Disc (galaxy)|disc]] scales. Assuming that the northern part of M82 is nearer to us, as most of the literature does, the observed sense of rotation implies trailing arms.<ref name="Mayyaetal2005">
{{cite journal
 | author=Mayya, Y. D. | author2=Carrasco, L. | author3=Luna, A.
 | date=2005
 | title=The Discovery of Spiral Arms in the Starburst Galaxy M82
 | journal=[[Astrophysical Journal]]
 | volume=628 | issue=1 | pages=L33–L36
 | bibcode=2005ApJ...628L..33M 
 | doi=10.1086/432644
|arxiv = astro-ph/0506275 | s2cid=17576187 }}</ref>

===Starburst region===
In 2005, the [[Hubble Space Telescope]] revealed 197 young massive clusters in the starburst core.<ref name="Barkeretal2008" /> The average mass of these clusters is around 200,000 [[solar masses]], hence the starburst core is a very energetic and high-density environment.<ref name="Barkeretal2008" /> Throughout the galaxy's center, young stars are being born 10 times faster than they are inside the entire [[Milky Way Galaxy]].<ref>{{Cite web |date=20 April 2006 |title=Happy Sweet Sixteen, Hubble Telescope! |url=https://www.newswise.com/articles/view/519818/ |access-date=30 July 2008 |website=Newswise}}</ref>

In the core of M82, the active starburst region spans a diameter of 500 [[parsec|pc]]. Four high surface brightness regions or clumps (designated A, C, D, and E) are detectable in this region at visible wavelengths.<ref name="Barkeretal2008" /> These clumps correspond to known sources at [[X-ray]], [[infrared]], and [[astronomical radio source|radio]] frequencies.<ref name="Barkeretal2008" /> Consequently, they are thought to be the least obscured starburst clusters from our vantage point.<ref name="Barkeretal2008" /> M82's unique bipolar outflow (or '[[galactic superwind|superwind]]') appears to be concentrated on clumps A and C, and is fueled by energy released by [[supernovae]] within the clumps which occur at a rate of about one every ten years.<ref name="Barkeretal2008" />

The [[Chandra X-ray Observatory]] detected fluctuating X-ray emissions about 600 light-years from the center of M82. Astronomers have postulated that this comes from the first known [[intermediate-mass black hole]], of roughly 200 to 5000 [[solar mass]]es.<ref name="Patrunoetal2006">
{{cite journal
 | author=Patruno, A. | author2=Portegies Zwart, S. | author3=Dewi, J. | author4=Hopman, C.
 | date=2006
 | title=The ultraluminous X-ray source in M82: an intermediate-mass black hole with a giant companion
 | journal=[[Monthly Notices of the Royal Astronomical Society: Letters]]
 | volume=370 | issue=1 | pages=L6–L9
 | bibcode=2006MNRAS.370L...6P 
 | doi=10.1111/j.1745-3933.2006.00176.x
| doi-access=free |arxiv = astro-ph/0602230 | s2cid=10694200 }}</ref> M82, like most galaxies, hosts a [[supermassive black hole]] at its center.<ref name=gaffney/> This one has mass of approximately 3 × 10<sup>7</sup> solar masses, as measured from stellar dynamics.<ref name=gaffney>
{{cite journal
 | author=Gaffney, N. I. | author2=Lester, D. F. | author3=Telesco, C. M.
 | name-list-style=amp
 | date = 1993
 | title = The stellar velocity dispersion in the nucleus of M82
 | journal=[[Astrophysical Journal Letters]]
 | volume = 407 | pages = L57–L60
 | doi = 10.1086/186805
 | bibcode = 1993ApJ...407L..57G
}}</ref>

===Unknown object===
In April 2010, radio astronomers working at the [[Jodrell Bank Observatory]] of the [[University of Manchester]] in the [[United Kingdom|UK]] reported an object in M82 that had started sending out radio waves, and whose emission did not look like anything seen anywhere in the universe before.<ref name="NewScientist">{{cite web|url=https://www.newscientist.com/article/dn18775-mysterious-radio-waves-emitted-from-nearby-galaxy.html|title=Mysterious radio waves emitted from nearby galaxy|access-date=14 April 2018}}</ref>

There have been several theories about the nature of this object, but currently no theory entirely fits the observed data.<ref name="NewScientist"/> It has been suggested that the object could be an unusual "micro quasar", having very high radio luminosity yet low X-ray luminosity, and being fairly stable, it could be an analogue of the low X-ray luminosity galactic microquasar [[SS 433]].<ref name="SS433Analogue">{{Cite journal |last1=Joseph |first1=T. D. |last2=Maccarone |first2=T. J. |last3=Fender |first3=R. P. |date=July 2011 |title=The unusual radio transient in M82: an SS 433 analogue? |journal=Monthly Notices of the Royal Astronomical Society: Letters |language=en |volume=415 |issue=1 |pages=L59–L63 |arxiv=1107.4988 |doi=10.1111/j.1745-3933.2011.01078.x |doi-access=free |bibcode=2011MNRAS.415L..59J |issn=1745-3933}}</ref> However, all known [[microquasar]]s produce large quantities of X-rays, whereas the object's X-ray flux is below the measurement threshold.<ref name="NewScientist"/> The object is located at several arcseconds from the center of M82 which makes it unlikely to be associated with a supermassive black hole. It has an apparent [[Superluminal motion|superluminal]] motion of four times the speed of light relative to the galaxy center.<ref name="arxiv.org">{{Cite journal |arxiv = 1003.0994|doi = 10.1111/j.1745-3933.2010.00845.x|title = Discovery of an unusual new radio source in the star-forming galaxy M82: Faint supernova, supermassive black hole or an extragalactic microquasar?|journal = Monthly Notices of the Royal Astronomical Society: Letters|volume = 404|issue = 1|pages = L109–L113|year = 2010|last1 = Muxlow|first1 = T. W. B.|last2 = Beswick|first2 = R. J.|last3 = Garrington|first3 = S. T.|last4 = Pedlar|first4 = A.|last5 = Fenech|first5 = D. M.|last6 = Argo|first6 = M. K.|last7 = Van Eymeren|first7 = J.|last8 = Ward|first8 = M.|last9 = Zezas|first9 = A.|last10 = Brunthaler|first10 = A.|last11 = Rich|first11 = R. M.|last12 = Barlow|first12 = T. A.|last13 = Conrow|first13 = T.|last14 = Forster|first14 = K.|last15 = Friedman|first15 = P. G.|last16 = Martin|first16 = D. C.|last17 = Morrissey|first17 = P.|last18 = Neff|first18 = S. G.|last19 = Schiminovich|first19 = D.|last20 = Small|first20 = T.|last21 = Donas|first21 = J.|last22 = Heckman|first22 = T. M.|last23 = Lee|first23 = Y. -W.|last24 = Milliard|first24 = B.|last25 = Szalay|first25 = A. S.|last26 = Yi|first26 = S.| doi-access=free |bibcode = 2010MNRAS.404L.109M|s2cid = 119302437}}</ref><ref>{{Cite web |last=O'Brien |first=Tim |date=14 April 2010 |title=Mystery object in Starburst Galaxy M82 – Jodrell Bank Centre for Astrophysics |url=https://www.jb.man.ac.uk/news/2010/M82mystery/ |access-date=14 April 2018 |website=[[University of Manchester]]}}</ref> Apparent superluminal motion is consistent with relativistic jets in massive black holes and does not indicate that the source itself is moving above lightspeed.<ref name="arxiv.org"/>

==Starbursts==
M82 is being physically affected by its larger neighbor, the [[spiral galaxy|spiral]] [[Messier 81|M81]].  Tidal forces caused by [[gravity]] have deformed M82, a process that started about 100 million years ago.  This interaction has caused star formation to increase tenfold compared to "normal" galaxies.

M82 has undergone at least one tidal encounter with M81 resulting in a large amount of gas being funneled into the galaxy's core over the last 200 Myr.<ref name="Barkeretal2008" /> The most recent such encounter is thought to have happened around 2–5{{e|8}} years ago and resulted in a concentrated starburst together with a corresponding marked peak in the cluster age distribution.<ref name="Barkeretal2008" /> This starburst ran for up to ~50 Myr at a rate of ~10 ''M''<sub>⊙</sub> per year.<ref name="Barkeretal2008" /> Two subsequent starbursts followed, the last (~4–6 Myr ago) of which may have formed the core clusters, both super star clusters (SSCs) and their lighter counterparts.<ref name="Barkeretal2008" />

Stars in M82's disk seem to have been formed in a burst 500 million years ago, leaving its disk littered with hundreds of clusters with properties similar to globular clusters (but younger), and stopped 100 million years ago with no star formation taking place in this galaxy outside the central starburst and, at low levels since 1 billion
years ago, on its [[galactic halo|halo]]. A suggestion to explain those features is that M82 was previously a [[low surface brightness galaxy]] where star formation was triggered due to interactions with its giant neighbor.<ref name="Divakaraetal2009">
{{cite journal
 | author=Divakara Mayya, Y. | author2=Carrasco, Luis
 | date=2009
 | title=M82 as a Galaxy: Morphology and Stellar Content of the Disk and Halo
 | journal=Revista Mexicana de Astronomía y Astrofísica, Serie de Conferencias
 | volume= 37
 | pages= 44–55
 | bibcode=2009arXiv0906.0757D
 |arxiv = 0906.0757 }}</ref>
Ignoring any difference in their respective distances from the Earth, the centers of M81 and M82 are visually separated by about 130,000 light-years.<ref>Declination separation of 36.87{{prime}} and Right Ascension separation of 9.5{{prime}} gives via [[Pythagorean theorem]] a visual separation of 38.07{{prime}}; Average distance of 11.65 Mly × sin(38.07{{prime}}) = 130,000 ly visual separation.</ref> The actual separation is {{val|300|+300|-200|u=kly}}.<ref>Separation = sqrt(D<sub>M81</sub><sup>2</sup> + D<sub>M82</sub><sup>2</sup> – 2 D<sub>M81</sub> D<sub>M82</sub> Cos(38.07{{prime}})) assuming the error direction is about the same for both objects.</ref><ref name="Karachentsevetal2006">
{{cite journal
 | author=Karachentsev, I. D. | author2=Kashibadze, O. G.
 | date=2006
 | title=Masses of the local group and of the M81 group estimated from distortions in the local velocity field
 | journal=Astrophysics| volume=49 | issue=1 | pages=3–18
 | bibcode=2006Ap.....49....3K
 | doi=10.1007/s10511-006-0002-6
| s2cid=120973010
 }}</ref>

==Supernovae==
As a starburst galaxy, Messier 82 is prone to frequent supernova, caused by the collapse of young, massive stars. The first (although false) supernova candidate reported was SN 1986D, initially believed to be a supernova inside the galaxy until it was found to be a variable short-wavelength infrared source instead.<ref name="sedsSN">{{cite web |title=Messier Object 82 |url=https://www.messier.seds.org/m/m082.html |website=www.messier.seds.org |access-date=14 July 2020 |archive-date=14 July 2020 |archive-url=https://web.archive.org/web/20200714002824/https://www.messier.seds.org/m/m082.html |url-status=dead }}</ref>

The first confirmed supernova recorded in the galaxy was SN 2004am, discovered in March 2004 from images taken in November 2003 by the [[Lick Observatory]] Supernova Search. It was later determined to be a [[Type II supernova]].<ref name="SN2004am">{{cite web |title=SN 2004am {{!}} Transient Name Server |url=https://wis-tns.weizmann.ac.il/object/2004am |website=wis-tns.weizmann.ac.il |access-date=14 July 2020}}</ref> In 2008, a radio transient was detected in the galaxy, designated SN 2008iz and thought to be a possible radio-only supernova, being too obscured in visible light by dust and gas clouds to be detectable.<ref name="SN2008iz">{{cite web |title=SN 2008iz {{!}} Transient Name Server |url=https://wis-tns.weizmann.ac.il/object/2008iz |website=wis-tns.weizmann.ac.il |access-date=14 July 2020}}</ref> A similar radio-only transient was reported in 2009, although never received a formal designation and was similarly unconfirmed.<ref name="sedsSN"/>

Prior to accurate and thorough supernova surveys, many other supernovae likely occurred in previous decades. The [[European VLBI Network]] studied a number of potential supernova remnants in the galaxy in the 1980s and 90s. One supernova remnant displayed clear expansion between 1986 and 1997 that suggested it originally went supernova in the early 1960s, and two other remnants show possible expansion that could indicate an age almost as young, but could not be confirmed at the time.<ref>{{cite journal |last1=Pedlar |first1=A. |last2=Muxlow |first2=T. W. B. |last3=Garrett |first3=M. A. |last4=Diamond |first4=P. |last5=Wills |first5=K. A. |last6=Wilkinson |first6=P. N. |last7=Alef |first7=W. |title=VLBI observations of supernova remnants in Messier 82 |journal=Monthly Notices of the Royal Astronomical Society |date=August 1999 |volume=307 |issue=4 |pages=761–768 |doi=10.1046/j.1365-8711.1999.02642.x |bibcode=1999MNRAS.307..761P |doi-access=free }}</ref>

===2014 supernova===
{{Main|SN 2014J}}
On 21 January 2014 at 19.20 UT, a new distinct star was observed in M82, at apparent magnitude +11.7, by astrophysics lecturer [[Steve Fossey]] and four of his students, at the [[UCL Observatory|University of London Observatory]]. It had brightened to [[Apparent magnitude|magnitude]] +10.9 two days later. Examination of earlier observations of M82 found the supernova to figure on the intervening day as well as on 15 through 20 January, brightening from magnitude +14.4 to +11.3; it could not be found, to limiting magnitude +17, from images caught of 14 January. It was initially suggested that it could become as bright as magnitude +8.5, well within the visual range of small telescopes and large binoculars,<ref>{{Cite web |last=Armstrong |first=Mark |date=January 23, 2014 |title=Bright, young supernova outburst in Messier 82 |url=https://astronomynow.com/news/n1401/23supernova/ |url-status=live |archive-url=https://web.archive.org/web/20201202075129/http://www.astronomynow.com/news/n1401/23supernova/ |archive-date=2 December 2020 |access-date=14 April 2018 |website=[[Astronomy Now]]}}</ref> but peaked at fainter +10.5 on the last day of the month.<ref>{{Cite web |last=MacRobert |first=Alan |date=17 February 2014 |title=Supernova in M82 Passes Its Peak |url=https://skyandtelescope.org/astronomy-news/observing-news/supernova-in-m82-passes-its-peak/ |url-status=live |archive-url=https://web.archive.org/web/20140214050932/http://www.skyandtelescope.com/observing/home/Bright-Supernova-in-M82-241477661.html |archive-date=14 February 2014 |access-date=14 April 2018 |website=[[Sky & Telescope]]}}</ref> Preliminary analysis classified it as "a young, reddened [[Type Ia supernova]]". The [[International Astronomical Union]] (IAU) has designated it SN 2014J.<ref>{{Cite web |date=22 January 2014 |title=UCL students discover a supernova |url=https://www.ucl.ac.uk/mathematical-physical-sciences/news/2014/jan/supernova-messier-82-discovered-ucl-students |url-status=live |archive-url=https://web.archive.org/web/20140123054804/http://www.ucl.ac.uk/maps-faculty/maps-news-publication/maps1405 |archive-date=23 January 2014 |access-date=14 April 2018 |website=[[University College London]]}}</ref> [[SN 1993J]] was also at relatively close distance, in M82's larger companion galaxy [[Messier 81|M81]]. [[SN 1987A]] in the [[Large Magellanic Cloud]] was much closer. 2014J is the closest Type Ia supernova since [[SN 1972E]].<ref name="astronomerstelegram.org"/><ref name="Huffington Post" /><ref name="slate.com"/>
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==Gallery==
{{multiple images |align=center |direction=horizontal |header=M82 Galaxy |width= |footer=
|image1=M82 in LRGB from Planewave CDK24; Ha from Adam Block.jpg|caption1=M82 in HaLRGB from CDK24 in Julian, CA (18 April 2020)|width1=230
|image2=PIA23010-M82-CigarGalaxy-20190305.jpg|caption1=M82 galaxy (5 March 2019)|width2=230
|image3=M82 Chandra HST Spitzer.jpg|caption2=Composite image – [[Hubble Space Telescope|HST]] (vis);  [[Spitzer Space Telescope|Spitzer]] (ir); [[Chandra X-ray Observatory|Chandra]] (x-ray). |width3=200
|image4=M82(2).jpg |caption3=Chandra X-ray observatory image of the galaxy. |width4=160
|image5=Hubble views new supernova in Messier 82.jpg|caption4=[[Hubble]] views new supernova in Messier 82<ref>{{cite news|title=Hubble views new supernova in Messier 82|url=http://www.spacetelescope.org/images/potw1409a/|access-date=12 March 2014|newspaper=ESA / HUBBLE}}</ref> |width5=230
|image6=M 82 supernova.jpg |caption5=M82 – Dec 2013; supernova – Jan 2014 (bottom) |width6=125
}}
--->

==Gallery==
<gallery class="center">
File:M82 CDK PA358 BlurX Large 06.jpg|Messier 82 imaged by amateur astronomer W4SM with 17" PlaneWave CDK astrograph
File:M82 Cigar Galaxy.png|M82 cigar galaxy with its hydrogen emissions taken in France by amateur astrophotographer Anthony MICHEL<ref>{{Cite web|url=https://app.astrobin.com/i/gghjj6|title = M 82 - Cigar Galaxy}}</ref>
</gallery>

==See also==
* [[List of Messier objects]]
* {{annotated link|Baby Boom Galaxy}}

==Notes==
{{notelist}}

==References==
{{Reflist|30em}}

==External links==
{{Commons}}
* [http://messier.seds.org/m/m082.html M82, SEDS Messier pages]
* [https://chandra.harvard.edu/photo/2006/m82/ M82 at Chandra]
* [https://web.archive.org/web/20060427105058/http://www.spitzer.caltech.edu/Media/releases/ssc2006-09/index.shtml SST: Galaxy on Fire!]
* [http://nedwww.ipac.caltech.edu/cgi-bin/nph-objsearch?objname=m82&extend=no&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 M82 at NASA/IPAC EXTRAGALACTIC DATABASE]
*[https://esahubble.org/images/?search=m82 ESA/Hubble images of M82]{{WikiSky}}
* [https://web.archive.org/web/20090610215549/http://www.dsi-astronomie.de/M82NAO8.html M82 The Cigar Galaxy]
* [https://web.archive.org/web/20111008003214/http://www.stargazer-observatory.com/M%2082.html M82 images with 2 semiprofessional amateur-telescopes as a result of collaboration between 2 observatories]
* [http://deepspacemap.com/#?l=69.6772,31.037,11 M82 at Deep Space Map]
{{Ursa Major}}
{{Messier objects}}
{{Ngc35}}
{{Portal bar|Astronomy|Stars|Outer space}}
{{Authority control}}
{{Sky|09|55|52.9200|+|69|40|46.140|11500000}}

{{DEFAULTSORT:Messier 082}}
[[Category:Starburst galaxies]]
[[Category:Irregular galaxies]]
[[Category:M81 Group]]
[[Category:Ursa Major]]
[[Category:Messier objects|082]]
[[Category:NGC objects]]
[[Category:UGC objects|05322]]
[[Category:Principal Galaxies Catalogue objects|028655]]
[[Category:Arp objects|337]]
[[Category:3C objects|231]]
[[Category:Discoveries by Johann Elert Bode]]
[[Category:Astronomical objects discovered in 1774]]
[[Category:Radio galaxies]]
[[Category:MCG objects|+12-10-011]]
[[Category:IRAS catalogue objects|09517+6954]]