View source for Astronomy:R136a1

{{short description|Wolf–Rayet star with one of the highest mass and luminosity of any known star}}
{{Starbox begin
| name = R136a1
}}
{{Starbox image
| image = [[File:R136a1 star.jpg|280px]]
| caption = A near-infrared image of the [[Astronomy:R136|R136]] cluster. R136a1 is at the center with [[Astronomy:R136a2|R136a2]] close by, [[Astronomy:R136a3|R136a3]] below right, and [[Astronomy:R136b|R136b]] to the left.
| credit = [[Organization:European Southern Observatory|ESO]]/[[Astronomy:Very Large Telescope|VLT]]
}}
{{Starbox observe
| constell = [[Astronomy:Dorado|Dorado]]
| epoch = [[Astronomy:J2000.0|J2000.0]]
| equinox = [[Astronomy:J2000.0|J2000.0]]
| ra = {{RA|5|38|42.39}}<ref name=census/>
| dec = {{DEC|−69|06|02.91}}<ref name=census/>
| appmag_v = 12.23<ref name="census">{{cite journal|last1=Doran|first1=E. I.|last2=Crowther|first2=P. A.|last3=de Koter|first3=A.|last4=Evans|first4=C. J.|last5=McEvoy|first5=C.|last6=Walborn|first6=N. R.|last7=Bastian|first7=N.|last8=Bestenlehner|first8=J. M.|last9=Gräfener|first9=G.|last10=Herrero|first10=A.|last11=Kohler|first11=K.|last12=Maiz Apellaniz|first12=J.|last13=Najarro|first13=F.|last14=Puls|first14=J.|last15=Sana|first15=H.|last16=Schneider|first16=F. R. N.|last17=Taylor|first17=W. D.|last18=van Loon|first18=J. Th.|last19=Vink|first19=J. S.|title=The VLT-FLAMES Tarantula Survey - XI. A census of the hot luminous stars and their feedback in 30 Doradus|journal=Astronomy & Astrophysics|volume=558|pages=A134|arxiv=1308.3412|date=2013|doi=10.1051/0004-6361/201321824|bibcode=2013A&A...558A.134D|s2cid=118510909}}</ref>
}}
{{Starbox character
| type = [[Astronomy:Wolf–Rayet star|Wolf–Rayet star]]
| class = [[Astronomy:Wolf–Rayet star|WN5h]]<ref name=hainich>{{Cite journal | doi = 10.1051/0004-6361/201322696| title = The Wolf–Rayet stars in the Large Magellanic Cloud| journal = Astronomy & Astrophysics| volume = 565| pages = A27| year = 2014| last1 = Hainich | first1 = R.| last2 = Rühling | first2 = U.| last3 = Todt | first3 = H.| last4 = Oskinova | first4 = L. M.| last5 = Liermann | first5 = A.| last6 = Gräfener | first6 = G.| last7 = Foellmi | first7 = C.| last8 = Schnurr | first8 = O.| last9 = Hamann | first9 = W. -R. | arxiv = 1401.5474| bibcode = 2014A&A...565A..27H| s2cid = 55123954}}</ref>
| b-v=0.03<ref name=census/>
| u-b=
|appmag_1_passband=
|appmag_1=
|appmag_2_passband=
|appmag_2=
}}
{{Starbox astrometry
| dist_ly = 163,000
| dist_pc = 49,970<ref name=Nature>{{cite journal|last=Pietrzyński|first=G|author2=D. Graczyk |author3=W. Gieren |author4=I. B. Thompson |author5=B. Pilecki |author6=A. Udalski |author7=I. Soszyński |display-authors=0 |title=An eclipsing-binary distance to the Large Magellanic Cloud accurate to two per cent|journal=Nature|date=7 March 2013|volume=495|issue=7439|pages=76–79|doi=10.1038/nature11878|pmid=23467166|arxiv = 1303.2063 |bibcode = 2013Natur.495...76P |s2cid=4417699}}</ref>
| absmag_v = −8.18<ref name=bestenlehner2020>{{cite journal |bibcode=2020MNRAS.499.1918B |title=The R136 star cluster dissected with Hubble Space Telescope/STIS. II. Physical properties of the most massive stars in R136 |last1=Bestenlehner |first1=Joachim M. |last2=Crowther |first2=Paul A. |last3=Caballero-Nieves |first3=Saida M. |last4=Schneider |first4=Fabian R. N. |last5=Simón-Díaz |first5=Sergio |last6=Brands |first6=Sarah A. |last7=De Koter |first7=Alex |last8=Gräfener |first8=Götz |last9=Herrero |first9=Artemio |last10=Langer |first10=Norbert |last11=Lennon |first11=Daniel J. |last12=Maíz Apellániz |first12=Jesus |last13=Puls |first13=Joachim |last14=Vink |first14=Jorick S. |journal=Monthly Notices of the Royal Astronomical Society |year=2020 |volume=499 |issue=2 |page=1918 |doi=10.1093/mnras/staa2801 |arxiv=2009.05136 }}</ref>
}}
{{Starbox detail
| mass = {{val|196|34|27}}<ref name=Kalari/>
| luminosity = 4,677,000<ref name=Kalari/>
| radius =42.7<ref name=brands/>
| temperature = {{val|46,000|1,250|2,375|fmt=commas}}<ref name=brands/>
| gravity = 3.65<ref name=brands/>
| metal =
| rotational_velocity = 160<ref name=brands/>
| age_myr = {{val|1.14|0.17|0.14}}<ref name=brands>{{Cite journal |arxiv=2202.11080 |last1=Brands |first1=Sarah A. |last2=de Koter |first2=Alex |last3=Bestenlehner |first3=Joachim M. |last4=Crowther |first4=Paul A. |last5=Sundqvist |first5=Jon O. |last6=Puls |first6=Joachim |last7=Caballero-Nieves |first7=Saida M. |last8=Abdul-Masih |first8=Michael |last9=Driessen |first9=Florian A. |last10=García |first10=Miriam |last11=Geen |first11=Sam |date=2022-02-01 |title=The R136 star cluster dissected with Hubble Space Telescope/STIS. III. The most massive stars and their clumped winds |journal=Astronomy & Astrophysics |volume=663 |pages=A36 |doi=10.1051/0004-6361/202142742 |s2cid=247025548 |bibcode=2022A&A...663A..36B}}</ref>
}}
{{Starbox catalog
| names= BAT99&nbsp;108, RMC&nbsp;136a1, HSH95&nbsp;3, WO84&nbsp;1b, NGC&nbsp;2070&nbsp;MH&nbsp;498, CHH92&nbsp;1, P93&nbsp;954}}
{{Starbox reference
| Simbad = RMC+136a1
| ARICNS = <!--Code-->
}}
{{Starbox end
}}
'''R136a1''' (short for '''RMC 136a1''') is one of the [[Astronomy:List of most massive stars|most massive]] and [[Astronomy:List of most luminous stars|luminous stars known]], at {{Solar mass|196|link=y}} and nearly 4.7 million {{Solar luminosity|link=y}}, and is also one of the [[Astronomy:List of hottest stars|hottest]], at around {{val|46,000|fmt=commas|ul=K}}. It is a [[Astronomy:Wolf–Rayet star|Wolf–Rayet star]] at the center of [[Astronomy:R136|R136]], the central concentration of stars of the large [[Astronomy:NGC 2070|NGC 2070]] [[Astronomy:Open cluster|open cluster]] in the [[Astronomy:Tarantula Nebula|Tarantula Nebula]] (30 [[Astronomy:Dorado|Doradus]]) in the [[Astronomy:Large Magellanic Cloud|Large Magellanic Cloud]]. The cluster can be seen in the far southern celestial hemisphere with binoculars or a small telescope, at magnitude 7.25. R136a1 itself is 100 times fainter than the cluster and can only be resolved using [[Physics:Speckle interferometry|speckle interferometry]].

==Discovery==
[[File:ESO - Eso1030a (by).jpg|thumb|left|upright=1.6|Zooming in from the Tarantula Nebula to the R136 cluster, with R136a1/2/3 visible as the barely resolved knot at bottom right]]
In 1960, a group of astronomers working at the Radcliffe Observatory in [[Place:Pretoria|Pretoria]] made systematic measurements of the [[Astronomy:Apparent magnitude|brightness]] and [[Spectrum|spectra]] of bright stars in the Large Magellanic Cloud. Among the objects cataloged was [[Astronomy:R136|RMC 136]] (Radcliffe observatory Magellanic Cloud catalog number 136), the central "star" of the [[Astronomy:Tarantula Nebula|Tarantula Nebula]], which the observers concluded was probably a multiple star system. Subsequent observations showed that R136 was located in the middle of a giant region of ionized interstellar hydrogen, known as an [[Astronomy:H II region|H II region]], which was a center of intense [[Astronomy:Nebula|star formation]] in the immediate vicinity of the observed stars.<ref>{{Cite journal|title = The brightest stars in the Magellanic Clouds|last1 = Feast|first1 = M. W.|date = 1960|journal = Monthly Notices of the Royal Astronomical Society|last2 = Thackeray|first2 = A. D.|last3 = Wesselink|first3 = A. J.|volume = 121|issue = 4|page = 337|bibcode = 1960MNRAS.121..337F|doi=10.1093/mnras/121.4.337|doi-access = free}}</ref>

In 1979, [[Astronomy:ESO 3.6 m Telescope|ESO's 3.6&nbsp;m telescope]] was used to resolve R136 into three components; R136a, [[Astronomy:R136b|R136b]], and [[Astronomy:R136c|R136c]].<ref name=eso>{{cite journal|bibcode=1980A&A....84...50F|title=The central object R 136 in the gas nebula 30 Doradus - Structure, color, mass and excitation parameter|journal=Astronomy and Astrophysics|volume=84|issue=1–2|date=April 1980|pages=50–59|last1=Feitzinger|first1=J. V.|last2=Schlosser|first2=W.|last3=Schmidt-Kaler|first3=T|last4=Winkler|first4=C.}}</ref> The exact nature of R136a was unclear and a subject of intense discussion. Estimates that the brightness of the central region would require as many as 100 hot [[Astronomy:O-type star|O class stars]] within half a [[Astronomy:Parsec|parsec]] at the centre of the cluster led to speculation that a star 3,000 times the mass of the Sun was the more likely explanation.<ref name="EbbetsConti1982">{{cite journal|last1=Ebbets|first1=D. C.|last2=Conti|first2=P. S.|title=The optical spectrum of R136a - The central object of the 30 Doradus nebula|journal=The Astrophysical Journal|volume=263|year=1982|page=108|issn=0004-637X|doi=10.1086/160485|bibcode=1982ApJ...263..108E|doi-access=free}}</ref>

The first demonstration that R136a was a [[Astronomy:Star cluster|star cluster]] was provided by Weigelt and Beier in 1985. Using the [[Physics:Speckle interferometry|speckle interferometry]] technique, R136a was shown to be made up of 8 stars within 1 [[Arcsecond|arcsecond]] at the centre of the cluster, with R136a1 being the brightest.<ref name="weigelt">{{cite journal|bibcode=1985A&A...150L..18W|title=R136a in the 30 Doradus nebula resolved by holographic speckle interferometry|journal=Astronomy and Astrophysics|volume=150|pages=L18|last1=Weigelt|first1=G.|last2=Baier|first2=G.|year=1985}}</ref>

Final confirmation of the nature of R136a came after the launch of the [[Astronomy:Hubble Space Telescope|Hubble Space Telescope]]. Its [[Engineering:Wide Field and Planetary Camera|Wide Field and Planetary Camera]] (WFPC) resolved R136a into at least 12 components and showed that R136 contained over 200 highly [[Astronomy:Luminosity|luminous]] stars.<ref name=campbell/>  The more advanced [[Engineering:Wide Field and Planetary Camera 2|WFPC2]] allowed the study of 46 massive luminous stars within half a parsec of R136a and over 3,000 stars within a 4.7 parsec radius.<ref name=hunter>{{Cite journal|title = The Intermediate Stellar Mass Population in R136 Determined from Hubble Space Telescope Planetary Camera 2 Images|last1 = Hunter|first1 = Deidre A.|date = 1995|journal =The Astrophysical Journal|doi = 10.1086/175950|bibcode = 1995ApJ...448..179H|volume = 448|page = 179|last2 = Shaya|first2 = Edward J.|last3 = Holtzman|first3 = Jon A.|last4 = Light|first4 = Robert M.|last5 = O'Neil|first5 = Earl J. Jr.|last6 = Lynds|first6 = Roger|doi-access = free}}</ref>

==Visibility==
[[File:R136a1 sky position.gif|thumb|left|Sky position of R136a1 viewed from Argentina]]
In the night sky, R136 appears as a 10th magnitude object at the core of the NGC 2070 cluster embedded in the Tarantula Nebula in the Large Magellanic Cloud.<ref name=westerlund>{{cite journal|bibcode=1964MNRAS.128..311W|title=Wolf-Rayet stars in the Large Magellanic Cloud|last1=Westerlund|first1=B. E.|last2=Smith|first2=L. F.|journal=Monthly Notices of the Royal Astronomical Society|volume=128|issue=4|page=311|date=1964|doi=10.1093/mnras/128.4.311|doi-access=free}}</ref>  It required a 3.6&nbsp;metre telescope to detect R136a as a component of R136 in 1979,<ref name=eso/> and resolving R136a to detect R136a1 requires a space telescope or sophisticated techniques such as [[Astronomy:Adaptive optics|adaptive optics]] or speckle interferometry.<ref name="weigelt"/>

South of about the 20th parallel south, the LMC is circumpolar, meaning that it can be seen (at least in part) all night every night of the year, weather and light pollution permitting. In the Northern Hemisphere, it can be visible south of the 20th parallel north. This excludes North America (except southern Mexico), Europe, northern Africa and northern Asia.<ref name=sjfj>{{cite web|url=http://earthsky.org/clusters-nebulae-galaxies/the-large-magellanic-cloud|title=Large Magellanic Cloud is spectacular from Earth's Southern Hemisphere|date=December 26, 2014}}</ref>

==Surroundings==
The R136a system at the core of R136 is a dense luminous knot of stars containing at least 12 stars,<ref name=campbell>{{cite journal|last1=Campbell|first1=Bel|last2=Hunter|first2=Deidre A.|last3=Holtzman|first3=Jon A.|last4=Lauer|first4=Tod R.|last5=Shayer|first5=Edward J.|last6=Code|first6=Arthur|last7=Faber|first7=S. M.|last8=Groth|first8=Edward J.|last9=Light|first9=Robert M.|last10=Lynds|first10=Roger|last11=O'Neil|first11=Earl J. Jr.|last12=Westphal|first12=James A.|title=Hubble Space Telescope Planetary Camera images of R136|journal=The Astronomical Journal|volume=104|year=1992|page=1721|doi=10.1086/116355|bibcode=1992AJ....104.1721C|url=https://authors.library.caltech.edu/52364/1/1992AJ____104_1721C.pdf}}</ref> the most prominent being R136a1, [[Astronomy:R136a2|R136a2]], and [[Astronomy:R136a3|R136a3]], all of which are extremely luminous and massive WN5h stars. R136a1 is separated from [[Astronomy:R136a2|R136a2]], the second brightest star in the cluster, by 5,000 [[Astronomy:Astronomical unit|AU]].<ref name="arxiv">{{Cite journal |last1=Crowther |first1=P. A. |last2=Schnurr |first2=O. |last3=Hirschi |first3=R. |last4=Yusof |first4=N. |last5=Parker |first5=R. J. |last6=Goodwin |first6=S. P. |last7=Kassim |first7=H. A.  |year=2010 |title=The R136 star cluster hosts several stars whose individual masses greatly exceed the accepted 150 M<sub>⊙</sub> stellar mass limit |journal=[[Organization:Monthly Notices of the Royal Astronomical Society|Monthly Notices of the Royal Astronomical Society]] |volume=408 |issue=2 |page=731 |arxiv=1007.3284 |bibcode=2010MNRAS.408..731C |doi=10.1111/j.1365-2966.2010.17167.x  |s2cid=53001712 }}</ref>

R136 is located approximately 157,000 [[Astronomy:Light-year|light-year]]s from Earth in the Large Magellanic Cloud, positioned on the south-east corner of the galaxy at the centre of the [[Astronomy:Tarantula Nebula|Tarantula Nebula]], also known as 30 Doradus. R136 itself is just the central condensation of the much larger [[Astronomy:NGC 2070|NGC 2070]] [[Astronomy:Open cluster|open cluster]].<ref name=massey>{{Cite journal | doi = 10.1086/305126| title = Star Formation in R136: A Cluster of O3 Stars Revealed by ''Hubble'' Space Telescope ''Spectroscopy''| journal = The Astrophysical Journal| volume = 493| issue = 1| pages = 180–194| year = 1998| last1 = Massey | first1 = P. | last2 = Hunter | first2 = D. A. | bibcode = 1998ApJ...493..180M| doi-access = free}}</ref>
For such a distant star, R136a1 is relatively [[Astronomy:Extinction|unobscured]] by [[Astronomy:Cosmic dust|interstellar dust]]. The reddening causes the visual brightness to be reduced by about 1.8 magnitudes, but only around 0.22 magnitudes in the near infrared.<ref name=arxiv/>

==Distance==
The distance to R136a1 cannot be determined directly, but is assumed to be at the same distance as the Large Magellanic Cloud at around 50 kiloparsecs<ref name=vfts682>{{cite journal|last1=Bestenlehner|first1=J. M.|last2=Vink|first2=J. S.|last3=Gräfener|first3=G.|last4=Najarro|first4=F.|last5=Evans|first5=C. J.|last6=Bastian|first6=N.|last7=Bonanos|first7=A. Z.|last8=Bressert|first8=E.|last9=Crowther|first9=P. A.|last10=Doran|first10=E.|last11=Friedrich|first11=K.|last12=Hénault-Brunet|first12=V.|last13=Herrero|first13=A.|last14=de Koter|first14=A.|last15=Langer|first15=N.|last16=Lennon|first16=D. J.|last17=Maíz Apellániz|first17=J.|last18=Sana|first18=H.|last19=Soszynski|first19=I.|last20=Taylor|first20=W. D.|title=The VLT-FLAMES Tarantula Survey|journal=Astronomy & Astrophysics|volume=530|year=2011|pages=L14|doi=10.1051/0004-6361/201117043|bibcode=2011A&A...530L..14B|arxiv = 1105.1775 |s2cid=119305523}}</ref> or 163,000 light years.

==Properties==
[[File:Noirlab2220a Sharpest Image Ever of R136a1, Largest Known Star.jpg| thumb|Sharpest image ever of R136a1, right at the centre of this image, resolving a close companion]]

===Binary===
A possible binary companion to R136a1 has been resolved, although there is a 25% possibility that it is a chance alignment.<ref name=Kalari>{{cite journal| bibcode=2022ApJ...935..162K | title=Resolving the Core of R136 in the Optical | last1=Kalari | first1=Venu M. | last2=Horch | first2=Elliott P. | last3=Salinas | first3=Ricardo | last4=Vink | first4=Jorick S. | last5=Andersen | first5=Morten | last6=Bestenlehner | first6=Joachim M. | last7=Rubio | first7=Monica | journal=The Astrophysical Journal | year=2022 | volume=935 | issue=2 | page=162 | doi=10.3847/1538-4357/ac8424 | arxiv=2207.13078 | s2cid=251067072 | doi-access=free }}</ref>

[[Physics:X-ray|X-ray]] emission was detected from R136 using the [[Astronomy:Chandra X-ray Observatory|Chandra X-ray Observatory]]. R136a and R136c were both clearly detected, but R136a could not be resolved.<ref name=chu>{{cite journal|last1=Guerrero|first1=Martín A.|last2=Chu|first2=You‐Hua|title=An X‐Ray Survey of Wolf‐Rayet Stars in the Magellanic Clouds. I. TheChandraACIS Data Set|journal=The Astrophysical Journal Supplement Series|volume=177|issue=1|year=2008|pages=216–237|doi=10.1086/587059|bibcode=2008ApJS..177..216G|arxiv = 0802.0503 |s2cid=16684661}}</ref>  Another study separated the R136a1/2 pair from R136a3. R136a1/2 showed relatively soft x-rays not thought to indicate a colliding winds binary.<ref name="townsley">{{cite journal|last1=Townsley|first1=Leisa K.|last2=Broos|first2=Patrick S.|last3=Feigelson|first3=Eric D.|last4=Garmire|first4=Gordon P.|last5=Getman|first5=Konstantin V.|title=AChandraACIS Study of 30 Doradus. II. X-Ray Point Sources in the Massive Star Cluster R136 and Beyond|journal=The Astronomical Journal|volume=131|issue=4|year=2006|pages=2164–2184|doi=10.1086/500535|bibcode=2006AJ....131.2164T|arxiv = astro-ph/0601106 |s2cid=17370015}}</ref>

Rapid [[Physics:Doppler effect|Doppler]] [[Astronomy:Radial velocity|radial velocity]] variations would be expected from a pair of equal mass stars in a close orbit, but this has not been seen in the R136a1 spectrum. A high orbital inclination, a more distant binary, or a chance alignment of two distant stars cannot be completely ruled out but is thought to be unlikely. Highly unequal binary components are possible, but would not affect the modelling of R136a1's properties.<ref name=arxiv/>

===Classification===
[[File:Morgan-Keenan spectral classification.svg|thumb|upright=1.6|Comparison of main sequence stars]]
R136a1 is a high-luminosity WN5h star, placing it on the extreme top left corner of the [[Hertzsprung–Russell diagram]]. A [[Astronomy:Wolf–Rayet star|Wolf–Rayet star]] is distinguished by the strong, broad emission lines in its spectrum. This includes ionized [[Chemistry:Nitrogen|nitrogen]], [[Chemistry:Helium|helium]], [[Chemistry:Carbon|carbon]], [[Chemistry:Oxygen|oxygen]] and occasionally [[Chemistry:Silicon|silicon]], but with [[Chemistry:Hydrogen|hydrogen]] lines usually weak or absent. A WN5 star is classified on the basis of ionised helium emission being considerably stronger than the neutral helium lines, and having roughly equal emission strength from N<small>III</small>, N<small>IV</small>, and N<small>V</small>. The "h" in the spectral type indicates significant hydrogen emission in the spectrum, and hydrogen is calculated to make up 40% of the surface abundance by mass.<ref name=hainich/>

WNh stars as a class are massive luminous stars still burning hydrogen at their cores. The emission spectrum is produced in a powerful dense [[Astronomy:Stellar wind|stellar wind]], and the enhanced levels of helium and nitrogen arise from convectional mixing of [[Astronomy:CNO cycle|CNO cycle]] products to the surface.<ref name=wnh>{{cite journal|doi=10.1086/586885|title=On the Role of the WNH Phase in the Evolution of Very Massive Stars: Enabling the LBV Instability with Feedback|journal=The Astrophysical Journal|volume=679|issue=2|pages=1467–1477|year=2008|last1=Smith|first1=Nathan|last2=Conti|first2=Peter S.|bibcode=2008ApJ...679.1467S|arxiv = 0802.1742 |s2cid=15529810}}</ref>

===Mass===
<!--R136a1 is the most massive star known.<ref name="SPC-20180728">{{cite web |last=Redd |first=Nola Taylor |title=What Is the Most Massive Star? |url=https://www.space.com/41313-most-massive-star.html |date=July 28, 2018 |work=Space.com |access-date=July 28, 2018 }}</ref>-->

An evolutionary mass of {{solar mass|215}} is found from [[Astronomy:Hubble Space Telescope|HST]] visual spectra using a non-LTE line-blanketed CMFGEN<ref name=cmfgen>{{cite journal|last1=Hillier|first1=D. John|last2=Miller|first2=D. L.|title=The Treatment of Non‐LTE Line Blanketing in Spherically Expanding Outflows|journal=The Astrophysical Journal|volume=496|issue=1|year=1998|pages=407–427|issn=0004-637X|doi=10.1086/305350|bibcode=1998ApJ...496..407H|s2cid=121364509 |doi-access=free}}</ref> model atmosphere. R136a1 closely matches the expected properties for an initially rapidly rotating {{solar mass|251}} star with LMC [[Astronomy:Metallicity|metallicity]] after shining for about a million years.<ref name=bestenlehner2020/>

An earlier analysis using [[Physics:Ultraviolet|ultraviolet]] spectroscopy found a current mass of {{solar mass|315}} and an initial mass of {{solar mass|325}}.<ref name=crowther2016>{{cite journal|bibcode=2016MNRAS.458..624C|arxiv=1603.04994|title=The R136 star cluster dissected with Hubble Space Telescope/STIS. I. Far-ultraviolet spectroscopic census and the origin of He II λ1640 in young star clusters|journal=Monthly Notices of the Royal Astronomical Society|volume=458|issue=1|pages=624–659|last1=Crowther|first1=Paul A.|last2=Caballero-Nieves|first2=S. M.|last3=Bostroem|first3=K. A.|last4=Maíz Apellániz|first4=J.|last5=Schneider|first5=F. R. N.|last6=Walborn|first6=N. R.|last7=Angus|first7=C. R.|last8=Brott|first8=I.|last9=Bonanos|first9=A.|last10=De Koter|first10=A.|last11=De Mink|first11=S. E.|author11-link=Selma de Mink|last12=Evans|first12=C. J.|last13=Gräfener|first13=G.|last14=Herrero|first14=A.|last15=Howarth|first15=I. D.|last16=Langer|first16=N.|last17=Lennon|first17=D. J.|last18=Puls|first18=J.|last19=Sana|first19=H.|last20=Vink|first20=J. S.|year=2016|doi=10.1093/mnras/stw273|s2cid=119131482}}</ref> 
A current mass of {{solar mass|256}} is found in similar analysis using PoWR (Potsdam Wolf–Rayet) atmospheric models<ref name=powr>{{cite journal|last1=Hamann|first1=W.-R.|last2=Gräfener|first2=G.|title=Grids of model spectra for WN stars, ready for use|journal=Astronomy and Astrophysics|volume=427|issue=2|year=2004|pages=697–704|doi=10.1051/0004-6361:20040506|bibcode=2004A&A...427..697H|doi-access=free}}</ref> with optical and ultraviolet spectra and a [[Astronomy:Mass–luminosity relation|mass–luminosity relation]],<ref name=grafener/> assuming a single star.<ref name=hainich/>

R136a1 is undergoing extreme [[Astronomy:Stellar mass loss|mass loss]] through a [[Astronomy:Stellar wind|stellar wind]] reaching a velocity of {{val|2,600|150|fmt=commas|u=km/s}}. This is caused by intense [[Physics:Electromagnetic radiation|electromagnetic radiation]] from the very hot [[Astronomy:Photosphere|photosphere]] accelerating material away from the surface more strongly than gravity can retain it.<ref name=arxiv/> Mass loss is largest for high-luminosity stars with low surface gravity and enhanced levels of heavy elements in the photosphere. R136a1 loses {{solar mass|{{val|1.6|e=−4}}}} ({{val|3.21|e=18|u=kg/s}}) per year, over a billion times more than the Sun loses, and is expected to have shed about {{Solar mass|35}} since its formation.<ref name=bestenlehner2020/>

===Luminosity===
[[File:Comparison of the sizes of a red dwarf, the Sun, a B-type main sequence star, and R136a1.jpg|thumb|upright=1.2|Left to right: a [[Astronomy:Red dwarf|red dwarf]], the Sun, a B-type main sequence star, and R136a1]]
It was from 2010 to 2020 that the star was recognised as the [[Astronomy:List of most massive stars|most massive]] and [[Astronomy:List of most luminous stars|luminous star known]]. Previous estimates had placed the luminosity as low as {{Solar luminosity|1,500,000}}.<ref name =BAT99>{{Cite journal|title = The fourth catalogue of Population I Wolf-Rayet stars in the Large Magellanic Cloud|last1 = Breysacher|first1 = J.|date = 1999|journal = Astronomy and Astrophysics|doi = 10.1051/aas:1999240|last2 = Azzopardi|first2 = M.|volume = 137|issue = 1|pages = 117–145|last3 = Testor|first3 = G.|bibcode = 1999A&AS..137..117B|series = Astronomy and Astrophysics Supplement Series|doi-access = free}}</ref>

At around {{solar luminosity|4,677,000}}, R136a1 is one of the [[Astronomy:List of most luminous stars|most luminous stars known]], radiating more energy in four seconds than the Sun does in a year. If it replaced the Sun in the Solar System, it would outshine the Sun by 164,000 times (M<sub>V</sub> = −8.2) and would appear from Earth at magnitude −40. Its brightness at a distance of 10 parsecs, the absolute visual magnitude, would be −8.18, three magnitudes brighter than Venus ever appears from Earth. Its brightness at the distance of the nearest star to Earth, [[Astronomy:Proxima Centauri|Proxima Centauri]] (just over a parsec), would be about the same as the [[Astronomy:Full moon|full moon]].

R136a1 supplies c. 7% of the ionizing flux of the entire 30 Doradus region, as much as 70 [[Astronomy:O-type main-sequence star|O7 main-sequence star]]s. Along with [[Astronomy:R136a2|R136a2]], [[Astronomy:R136a3|a3]], and [[Astronomy:R136c|c]], it produces 43–46% of the [[Physics:Lyman continuum photons|Lyman continuum radiation]] of the whole R136 cluster.<ref name=arxiv/>

Massive stars lie close to the Eddington limit, the luminosity at which the radiation pressure acting outwards at the surface of the star equals the force of the star's gravity pulling it inward. Above the Eddington limit, a star generates so much energy that its [[Astronomy:Stellar atmosphere|outer layers]] are rapidly thrown off. This effectively restricts stars from shining at higher luminosities for long periods.<ref>{{cite journal |bibcode=2008AIPC..990..250V |title=Continuum driven winds from super-Eddington stars. A tale of two limits |author=A. J. van Marle |author2=S. P. Owocki |author3=N. J. Shaviv  |date=2008 |journal=AIP Conference Proceedings |volume=990 |pages=250–253 |doi=10.1063/1.2905555|arxiv = 0708.4207 |s2cid=118364586 }}</ref>  The classical Eddington luminosity limit is not applicable to stars such as R136a1 that are not in hydrostatic equilibrium, and its calculation is extremely complex for real stars. The empirical Humphrey-Davidson limit has been identified as a luminosity limit for observed stars,<ref name="Martins2015">{{cite book|last1=Martins|first1=Fabrice|title=Very Massive Stars in the Local Universe|volume=412|year=2015|pages=9–42|doi=10.1007/978-3-319-09596-7_2|chapter=Empirical Properties of Very Massive Stars|series=Astrophysics and Space Science Library|isbn=978-3-319-09595-0|bibcode=2015ASSL..412....9M|arxiv = 1404.0166 |s2cid=119229211}}</ref><ref name=hd>{{cite journal|last1=Humphreys|first1=Roberta M.|last2=Davidson|first2=Kris|title=The luminous blue variables: Astrophysical geysers|journal=Publications of the Astronomical Society of the Pacific|volume=106|year=1994|page=1025|doi=10.1086/133478|bibcode=1994PASP..106.1025H|doi-access=free}}</ref> but recent models have attempted to calculate useful theoretical Eddington limits applicable to massive stars.<ref name=grafener>{{cite journal|last1=Gräfener|first1=G.|last2=Vink|first2=J. S.|last3=de Koter|first3=A.|last4=Langer|first4=N.|title=The Eddington factor as the key to understand the winds of the most massive stars|journal=Astronomy & Astrophysics|volume=535|year=2011|pages=A56|doi=10.1051/0004-6361/201116701|bibcode=2011A&A...535A..56G|arxiv = 1106.5361 |s2cid=59396651}}</ref> R136a1 is currently around 70% of its Eddington luminosity.<ref name=arxiv/>

===Temperature===
[[File:56000K blackbody visible colour.svg|thumb|20x20px|The colour of a 46,000 K blackbody]]
R136a1 has a surface temperature of around {{convert|46,000|K|C F|lk=in}}, eight times as hot as the [[Astronomy:Sun|Sun]], and with peak radiation in the [[Physics:Extreme ultraviolet|extreme ultraviolet]].<ref name=bestenlehner2020/>

R136a1 has a B–V index of about 0.03, which is a typical colour for an [[Astronomy:F-type star|F-type star]]. The "U–V" colour from the [[Astronomy:Hubble Space Telescope|HST]] [[Engineering:Wide Field and Planetary Camera 2|WFPC2]] {{val|336|u=nm}} and {{val|555|u=nm}} filters is −1.28, more indicative of an extremely hot star.<ref name=hunter/> This variation of different colour indices relative to a blackbody is the result of interstellar dust causing reddening and extinction. The reddening (E<sub>B–V</sub>) can be used to estimate the level of visual extinction (A<sub>V</sub>). E<sub>B–V</sub> values of 0.29–0.37 have been measured, with considerable uncertainty due to contamination from close neighbours such as [[Astronomy:R136a2|R136a2]] 0.1" away, leading to A<sub>V</sub> around 1.80 and a de-reddened B–V (B–V<sub>0</sub>) of −0.30.<ref name=hainich/><ref name=arxiv/>

The [[Astronomy:Effective temperature|effective temperature]] of a star can be approximated from the colour, but this is not very accurate and spectral fitting to an atmospheric model is necessary to derive the temperature. Temperatures of 53,000–56,000 K are found for R136a1 using different atmospheric models. Older models had produced temperatures around {{val|45,000|u=K|fmt=commas}} and hence dramatically lower luminosities.<ref name=BAT99/>  The extreme temperature of the star causes its [[Physics:Planck's law|peak radiation]] to be around {{val|50|u=nm}} and nearly 99% of the radiation to be emitted outside the visual range (a [[Astronomy:Bolometric correction|bolometric correction]] around −5).

===Size===
[[File:Size comparison between R136a1 and sun.gif|thumb|right|A size comparison between R136a1 and the Sun]]
R136a1 is over forty times the radius of the Sun ({{convert|42.7|solar radius|km au|abbr=on|lk=on|frac=7|disp=semicolon}}) which corresponds to a volume nearly 80,000 times larger than the Sun.<ref name=bestenlehner2020/>

R136a1 does not have a well-defined visible surface like the Earth or the Sun. The [[Astronomy:Hydrostatic equilibrium|hydrostatic]] main body of the star is surrounded by a dense atmosphere being accelerated outwards into the stellar wind. An arbitrary point within this wind is defined as the surface for measuring the radius, and different authors may use different definitions. For example, a Rosseland optical depth of 2/3 corresponds approximately to a visible surface while a Rosseland depth of 20 or 100 corresponds more closely to a physical photosphere. Stellar temperatures are typically quoted at the same depth so that the radius and temperature correspond to the luminosity.<ref name=hainich/><ref name=arxiv/>

R136a1's dimensions are far smaller than the largest stars: [[Astronomy:Red supergiant|red supergiant]]s are {{solar radius|several hundred to over a thousand}}, tens of times larger than R136a1. Despite the large mass and modest dimensions, R136a1 has an average density less than 1% of the Sun's. At about 5 [[Kilogram|kg]]/m<sup>3</sup>, it is around 4 times denser than Earth's [[Astronomy:Atmosphere|atmosphere]] at [[Sea level|sea level]]; alternatively, less than a hundredth the density of [[Chemistry:Water|water]].

===Rotation===
The rotation rate of R136a1 cannot be measured directly since the [[Astronomy:Photosphere|photosphere]] is hidden by the dense [[Astronomy:Stellar wind|stellar wind]] and the photospheric absorption lines used to measure rotational doppler broadening are not present in the spectrum. A N<sub>V</sub> emission line at 2.1&nbsp;µm is produced relatively deep in the wind and can be used to estimate rotation. In R136a1 it has a [[Full width at half maximum|FWHM]] of about [[Angstrom|15&nbsp;Å]], indicating a slow or non rotating star, although it could be aligned with its pole facing Earth. R136a2 and a3 are rotating rapidly and the closest evolutionary models for R136a1 match a star still rotating with an equatorial speed of c.&nbsp;200&nbsp;km/s after c.&nbsp;1.75&nbsp;Myr.<ref name="arxiv"/>

==Evolution==

===Current state===
R136a1 is currently fusing hydrogen to helium, predominantly by the [[Astronomy:CNO cycle|CNO cycle]] due to the high temperatures at the core. Despite the Wolf–Rayet spectral appearance, it is a young star, just over a million years old. The emission spectrum is created by a dense stellar wind caused by the extreme luminosity, with the enhanced levels of helium and nitrogen being mixed from the core to the surface by strong convection. It is effectively a WR-type [[Astronomy:Main sequence|main sequence]] star.<ref name=wnh/>  Over 90% of the star is [[Astronomy:Convection zone|convective]], with a small non-convective layer at the surface.<ref name=kohler>{{cite journal|last1=Köhler|first1=K.|last2=Langer|first2=N.|last3=de Koter|first3=A.|last4=de Mink|first4=S. E.|author4-link=Selma de Mink|last5=Crowther|first5=P. A.|last6=Evans|first6=C. J.|last7=Gräfener|first7=G.|last8=Sana|first8=H.|last9=Sanyal|first9=D.|last10=Schneider|first10=F. R. N.|last11=Vink|first11=J. S.|title=The evolution of rotating very massive stars with LMC composition|journal=Astronomy & Astrophysics|volume=573|year=2014|pages=A71|doi=10.1051/0004-6361/201424356|bibcode=2015A&A...573A..71K|arxiv = 1501.03794 |s2cid=28962151}}</ref>

===Development===
[[File:Grand star-forming region R136 in NGC 2070 (captured by the Hubble Space Telescope).jpg|thumb|upright=1.2|The R136 cluster in a massive star forming region in the LMC ]]

Models of star formation by accretion from [[Astronomy:Molecular cloud|molecular cloud]]s predict an upper limit to the mass a star can achieve before its radiation prevents further accretion. The most simplistic accretion models at population I metallicities predict a limit as low as {{solar mass|40}}, but more complex theories allow masses several times higher.<ref name=zinnecker>{{cite journal|last1=Zinnecker|first1=Hans|last2=Yorke|first2=Harold W.|title=Toward Understanding Massive Star Formation*|journal=Annual Review of Astronomy and Astrophysics|volume=45|issue=1|year=2007|pages=481–563|doi=10.1146/annurev.astro.44.051905.092549|bibcode=2007ARA&A..45..481Z|arxiv = 0707.1279 |s2cid=119169578}}</ref>  An empirical limit of around {{solar mass|150}} has become widely accepted.<ref name=figer>{{cite journal|last1=Figer|first1=Donald F.|title=An upper limit to the masses of stars|journal=Nature|volume=434|issue=7030|year=2005|pages=192–194|doi=10.1038/nature03293|pmid=15758993|bibcode=2005Natur.434..192F|arxiv = astro-ph/0503193 |s2cid=4417561}}</ref>  R136a1 clearly exceeds all these limits, leading to development of new single star accretion models potentially removing the upper limit,<ref name="KuiperKlahr2011">{{cite journal|last1=Kuiper|first1=Rolf|title=Three-Dimensional Simulation of Massive Star Formation in the Disk Accretion Scenario|last2=Klahr|first2=Hubert|last3=Beuther|first3=Henrik|last4=Henning|first4=Thomas|journal=The Astrophysical Journal|volume=732|issue=1|year=2011|page=20|issn=0004-637X|doi=10.1088/0004-637X/732/1/20|bibcode=2011ApJ...732...20K|arxiv = 1102.4090 |s2cid=73681618}}</ref> and the potential for massive star formation by stellar mergers.<ref name=SC>{{cite journal |last1=Oh |first1=Sambaran |last2=Kroupa |first2=Pavel |last3=Oh |first3=Seungkyung |year=2012 |title=The emergence of super-canonical stars in R136-type star-burst clusters |journal=Monthly Notices of the Royal Astronomical Society |arxiv=1208.0826|bibcode = 2012MNRAS.426.1416B |volume=1208 |issue=2 |page=826 |doi=10.1111/j.1365-2966.2012.21672.x|s2cid=119202197 }}</ref><ref name=vink>{{cite journal|arxiv=1302.2021|last1= Vink|first1= Jorick S.|title= Very Massive Stars (VMS) in the Local Universe|last2= Heger|first2= Alexander|last3=  Krumholz|first3= Mark R.|last4= Puls|first4= Joachim|last5=  Banerjee|first5= S.|last6=  Castro|first6= N.|last7= Chen|first7= K. -J.|last8= Chene|first8= A. -N.|last9= Crowther|first9= P. A.|last10=  Daminelli|first10= A.|last11= Grafener|first11= G.|last12= Groh|first12= J. H.|last13= Hamann|first13= W. -R.|last14=  Heap|first14= S.|last15=  Herrero|first15= A.|last16= Kaper|first16= L.|last17= Najarro|first17= F.|last18= Oskinova|first18= L. M.|last19= Roman-Lopes|first19= A.|last20=  Rosen|first20= A.|last21= Sander|first21= A.|last22=  Shirazi|first22= M.|last23=  Sugawara|first23= Y.|last24= Tramper|first24= F.|last25=  Vanbeveren|first25= D.|last26= Voss|first26= R.|last27=  Wofford|first27= A.|last28=  Zhang|first28= Y.|year= 2013|doi=10.1017/S1743921314004657|volume=10|journal=Proceedings of the International Astronomical Union|pages=51–79|bibcode = 2015HiA....16...51V |s2cid= 118564450}}</ref>

As a single star formed from accretion, the properties of such a massive star are still uncertain. Synthetic spectra indicate that it would never have a main sequence luminosity class (V), or even a normal O type spectrum. The high luminosity, proximity to the Eddington limit, and strong stellar wind, would be likely to create an If* or WNh spectrum as soon as R136a1 became visible as a star. Helium and nitrogen are rapidly mixed to the surface due to the large convective core and high mass loss, and their presence in the stellar wind creates the characteristic Wolf–Rayet emission spectrum.<ref name=arxiv/> The ZAMS at very high masses curves back to cooler temperatures, and at LMC metallicities the maximum temperature predicted to be around 56,000 K for {{solar mass|150–200}} stars, so R136a1 would have been slightly cooler than some less massive main sequence stars.<ref name=kohler/>

During core hydrogen burning, the helium fraction in the core increases and according to the [[Physics:Virial theorem|virial theorem]] the core pressure and temperature will increase.<ref name=langer>{{cite journal|last1=Langer|first1=N.|title=Presupernova Evolution of Massive Single and Binary Stars|journal=Annual Review of Astronomy and Astrophysics|volume=50|issue=1|year=2012|pages=107–164|doi=10.1146/annurev-astro-081811-125534|bibcode=2012ARA&A..50..107L|arxiv = 1206.5443 |s2cid=119288581}}</ref> This leads to an increase in luminosity so that R136a1 is somewhat more luminous now than when it first formed. The temperature decreases slightly, but the outer layers of the star have inflated, driving even higher mass loss.<ref name=arxiv/>

===Future===
The future development of R136a1 is uncertain, and there are no comparable stars to confirm predictions. The evolution of massive stars depends critically on the amount of mass they can lose, and various models give different results, none of which entirely match observations. It is thought that WNh stars develop into [[Astronomy:Luminous blue variable|LBVs]] as hydrogen at the core starts to become depleted. This is an important phase of extreme mass loss which enables a star, at near solar metallicity, to transition to a hydrogen-free Wolf–Rayet star.<ref name="wnh"/> Stars with sufficiently strong mixing from the core to the surface, due to the very large convective core, high metallicity, or additional rotational mixing, may skip the LBV phase and evolve directly from the hydrogen-rich WNh phase to the hydrogen-poor WN phase.<ref name=meynet>{{cite journal|bibcode=2011BSRSL..80..266M|title=Red Supergiants, Luminous Blue Variables and Wolf–Rayet stars: the single massive star perspective|last1=Meynet|first1=Georges|last2=Georgy|first2=Cyril|last3=Hirschi|first3=Raphael|last4=Maeder|first4=André|last5=Massey|first5=Phil|last6=Przybilla|first6=Norbert|last7=Nieva|first7=M.-Fernanda
|date=January 2011|journal=Société Royale des Sciences de Liège, Bulletin|volume=80|pages=266–278|arxiv = 1101.5873 }}</ref> Hydrogen fusion lasts for a little over two million years, and the star's mass at the end is expected to be {{solar mass|70–80}}.<ref name=kohler/> A single star with LMC metallicity, even if it starts out rotating very rapidly, will be braked to near zero rotation by the end of hydrogen burning.<ref name=yusof/>

After core helium fusion starts, the remaining hydrogen in the atmosphere is rapidly lost and R136a1 will quickly contract to a hydrogen-free WNE star and the luminosity will decrease. Wolf–Rayet stars at this point are mostly helium and they lie on the Zero Age Helium Main Sequence (He-ZAMS), analogous to and parallel to the hydrogen-burning main sequence but at hotter temperatures.<ref name=kohler/>

During helium burning, carbon and oxygen will accumulate in the core and heavy mass loss continues. This eventually leads to the development of a WC spectrum, although at LMC metallicity a star is expected to spend most of the helium burning phase with a WN spectrum. Towards the end of helium burning, core temperature increase and mass loss cause an increase in both luminosity and temperature, with the spectral type becoming WO. Several hundred thousand years will be spent fusing helium, but the final stages of heavier element burning take no more than a few thousand years.<ref name=yusof/><ref name=groh2013>{{cite journal|bibcode=2013A&A...558A.131G|title=Fundamental properties of core-collapse supernova and GRB progenitors: Predicting the look of massive stars before death|journal=Astronomy & Astrophysics|volume=558|pages=A131|last1=Groh|first1=Jose H.|last2=Meynet|first2=Georges|last3=Georgy|first3=Cyril|last4=Ekström|first4=Sylvia|year=2013|doi=10.1051/0004-6361/201321906|arxiv = 1308.4681 |s2cid=84177572}}</ref> R136a1 will eventually shrink to a little over {{solar mass|50}}, with just {{solar mass|0.5}} of helium left surrounding the core.<ref name=yusof>{{cite journal|bibcode=2013MNRAS.433.1114Y|title=Evolution and fate of very massive stars|journal=Monthly Notices of the Royal Astronomical Society|volume=433|issue=2|page=1114|last1=Yusof|first1=Norhasliza|last2=Hirschi|first2=Raphael|last3=Meynet|first3=Georges|last4=Crowther|first4=Paul A.|last5=Ekström|first5=Sylvia|last6=Frischknecht|first6=Urs|last7=Georgy|first7=Cyril|last8=Abu Kassim|first8=Hasan|last9=Schnurr|first9=Olivier|year=2013|doi=10.1093/mnras/stt794|arxiv = 1305.2099 |s2cid=26170005}}</ref>

===Supernova===
[[File:Remnants of single massive stars.svg|thumb|upright=1.5|Predicted supernova remnants by star initial mass and metallicity]]
Any star which produces a carbon–oxygen (C–O) core more massive than the maximum for a white dwarf (c. {{solar mass|1.4}}) will inevitably suffer core collapse. This usually happens when an iron core has been produced and fusion can no longer produce the energy required to prevent core collapse, although it can happen in other circumstances.

A C–O core between about {{solar mass|64}} and {{solar mass|133}} will become so hot that the gamma radiation will spontaneously produce electron–positron pairs and the sudden loss of energy in the core will cause it to collapse as a [[Astronomy:Pair-instability supernova|pair-instability supernova]] (PISN), sometimes called a pair-creation supernova (PCSN). A PISN is usually only produced in very low metallicity stars that do not lose sufficient mass to keep their C–O core sizes below {{solar mass|64}}. This can also occur at LMC metallicity for very massive stars, but the predicted C–O core size for R136a1 is below {{solar mass|50}} so a PISN is unlikely.<ref name=yusof/>

Iron core collapse may produce a [[Astronomy:Supernova|supernova]] explosion, and sometimes a [[Astronomy:Gamma-ray burst|gamma-ray burst]] (GRB). The type of any supernova explosion will be a type I since the star has no hydrogen; [[Astronomy:Type Ib and Ic supernovae|type Ic]] since it has almost no helium.<ref name=yusof/> Particularly massive iron cores may collapse the entire star into a [[Astronomy:Black hole|black hole]] with no visible explosion, or a sub-luminous supernova as radioactive <sup>56</sup>Ni falls back onto the black hole.<ref name=oconnor>{{cite journal|last1=O'Connor|first1=Evan|title=Black Hole Formation in Failing Core-Collapse Supernovae|last2=Ott|first2=Christian D.|journal=The Astrophysical Journal|volume=730|issue=2|year=2011|page=70|issn=0004-637X|doi=10.1088/0004-637X/730/2/70|bibcode=2011ApJ...730...70O|arxiv = 1010.5550 |s2cid=34865398}}</ref>

A type Ic supernova can produce a GRB if the star is rotating and has an appropriate mass. R136a1 is expected to lose almost all its spin long before core collapse so a GRB is unlikely.<ref name=yusof/>

The remnant from a type Ic core collapse supernova is either a [[Astronomy:Neutron star|neutron star]] or black hole, depending on the mass of the progenitor core. For a star as massive as R136a1, the remnant will very likely be a black hole instead of a neutron star.<ref name="groh2013" />

==See also==
* [[Astronomy:Hypergiant|Hypergiant]]
* [[Astronomy:List of most luminous stars|List of most luminous stars]]
* [[Astronomy:List of most massive stars|List of most massive stars]]
* [[Astronomy:VY Canis Majoris|VY Canis Majoris]] — one of the largest stars and red supergiants
* [[Astronomy:BAT99-98|BAT99-98]] — one of the most massive stars
* [[Astronomy:R136a2|R136a2]]

==References==
{{Reflist}}

{{Stars of Dorado}}
{{Sky|05|38|42.43|-|69|06|02.2|165000}}

[[Category:Stars in the Large Magellanic Cloud]]
[[Category:Tarantula Nebula]]
[[Category:Extragalactic stars]]
[[Category:Wolf–Rayet stars]]
[[Category:Large Magellanic Cloud]]

{{Sourceattribution|R136a1}}