View source for Astronomy:VFTS 682

{{Short description|Wolf Rayet star in the constellation Dorado}}
{{Starbox begin
| name = VFTS 682
}}
{{Starbox image
| image = [[File:The brilliant star VFTS 682 in the Large Magellanic Cloud.jpg|280px]]
| caption = VFTS 682 is at the very centre of this image of the Tarantula Nebula
| credit = ESO/M.-R. Cioni/VISTA Magellanic Cloud survey. Acknowledgment: Cambridge Astronomical Survey Unit
}}
{{Starbox observe
| epoch = J2000
| constell = [[Astronomy:Dorado|Dorado]]
| ra = {{RA|05|38|55.51}}<ref name=2mass/>
| dec = {{DEC|-69|04|26.72}}<ref name=2mass/>
| appmag_v = 16.08<ref name=evans/>
}}
{{Starbox character
| class=WN5h<ref name=bressert/>
| b-v=-0.58<ref name=evans/>
| u-b=-0.349<ref name=parker/>
| variable=
}}
{{Starbox astrometry
| dist_ly = 164,000
| dist_pc = 50,000
| absmag_v= {{val|p=-|6.83|0.12}}<ref name=VFTS682/>
| absmag_bol=-11.5
| radial_v=300<ref name=VFTS682/>
}}
{{Starbox detail
| mass = {{val|137.8|27.5|15.9}}<ref name=schneider/>
| radius = {{val|20.2|2.5|2.3}}<ref name=schneider/>
| gravity = <!--Surface gravity (given as the base 10 logarithm expressed in cgs units)-->
| luminosity = 3,200,000<ref name=VFTS682/>
| temperature = {{val|54450|1960|fmt=commas}}<ref name=schneider/>
| rotational_velocity = <200<ref name=schneider/>
| age_myr = {{val|1.0|0.2}}<ref name=schneider/>
}}
{{Starbox catalog
| names = [[Astronomy:2MASS|2MASS]]&nbsp;J05385552-6904267, IRSF&nbsp;J05385552-6904267, DENIS&nbsp;J053855.4-690425, DENIS&nbsp;J053855.5-690426, Dor&nbsp;IRS&nbsp;153
}}
{{Starbox reference
| Simbad = VFTS+682
}}
{{Starbox end}}

'''VFTS 682''' is a [[Astronomy:Wolf–Rayet star|Wolf–Rayet star]] in the [[Astronomy:Large Magellanic Cloud|Large Magellanic Cloud]]. It is located over {{convert|29|pc|ly|lk=on}} north-east of the massive [[Astronomy:Star cluster|cluster]] [[Astronomy:R136|R136]] in the [[Astronomy:Tarantula Nebula|Tarantula Nebula]].<ref name=VFTS682/> It is 138 times the mass of the sun and 3.2 million times more luminous which makes it one of the [[Astronomy:List of most massive stars|most massive]] and [[Astronomy:List of most luminous stars|most luminous]] stars known.

==Discovery==
VFTS 682 is a prominent infrared source in the Large Magellanic Cloud and has been catalogued numerous times. In 1992 it was identified as entry 153 in a list of possible [[Astronomy:Protostar|protostar]]s.<ref name=hyland/> In 2009 it was again classified as a probable [[Astronomy:Young stellar object|young stellar object]] on account of its exceptional infrared luminosity.<ref name=griendl/>

The [[Astronomy:Very Large Telescope|VLT]]-FLAMES Tarantula survey (VFTS) examined 800 massive stars in detail and determined a spectral type of WN5h for VFTS 682.  It is heavily reddened and visually several magnitudes fainter than other stars of similar luminosity and temperature in the 30 Doradus region.<ref name=evans/>

==Runaway==
VFTS 682 is in the large star-forming region of the Tarantula Nebula, but is not within a dense massive cluster.  The existence of an extremely massive and extremely young star in some isolation is unexpected since these stars are expected to form only from the most massive and dense molecular clouds and hence to form in large groups such as [[Astronomy:R136|R136]] as the result of competitive accretion or stellar mergers.  The formation of isolated massive star would require different models to allow monolithic disk accretion of very massive stars.

VFTS 682 is close enough to R136 that it might have formed there and been ejected.  No bow shock has been detected and it has a space velocity lower than most [[Astronomy:Runaway star|runaway]]s, but large enough and in the right direction that it could be from R136.<ref name=banerjee/>

==Properties==
The star's high mass of {{solar mass|138|link=y}} compresses its core to a high temperature and causes very rapid [[Physics:Nuclear fusion|fusion]] via the [[Astronomy:CNO cycle|CNO cycle]], leading to the extremely high luminosity of {{solar luminosity|3.2 million|link=y}}. The star is 22 times the radius of the sun but because of its high temperature it emits 3.2 million times more energy, mostly at ultraviolet wavelengths so it is only 43,000 times as bright as the sun visually.  Nearly 99% ([[Astronomy:Extinction|A<sub>V</sub>]] = 4.5) of the ultraviolet and visual radiation is then blocked by intervening interstellar material. The luminosity, intense UV radiation, and chemical makeup of the star's surface layers results in a [[Astronomy:Stellar wind|stellar wind]] with a speed up to {{convert|2600|km/s|abbr=on}}.<ref name=banerjee/>

==Evolution==
Stars as massive as VFTS 682 with [[Astronomy:Metallicity|metallicity]] typical of the Large Magellanic Cloud will maintain near-homogeneous chemical structure due to strong convection and rotational mixing. This produces strong helium and nitrogen surface abundance enhancement even during core hydrogen burning. Their rotation rates will also decrease significantly due to mass loss and envelope inflation, so that [[Astronomy:Gamma-ray burst|gamma-ray burst]]s are unlikely when this type of star reaches core collapse.

Very massive stars are expected to develop directly from hydrogen-rich young stars showing an Of or WNh spectrum into classical hydrogen-poor [[Astronomy:Wolf–Rayet star|Wolf–Rayet star]]s, possibly with a short period as a luminous blue variable  They will continue to lose mass rapidly, passing through WN, WC, and WO stages before exploding as a [[Astronomy:Type Ib and Ic supernovae|type Ic]] [[Astronomy:Supernova|supernova]] and leaving behind a [[Astronomy:Black hole|black hole]].  It is unclear whether the resulting supernova would be under-luminous, or even invisible, as the result of collapsing into the black hole, or over-luminous due to a large mass of ejected radioactive Ni<sub>56</sub>.

The total lifetime would be around 2-3 million years, with the last half million years or so spent as a Wolf Rayet star burning helium at the core and a very short period burning heavier elements.<ref name=yusof/><ref name=kohler/>

==References==
{{reflist|refs=

<ref name=2mass>{{cite journal |bibcode=2003yCat.2246....0C |title=VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003) |journal=CDS/ADC Collection of Electronic Catalogues |pages=II/246 |volume=2246 |last1=Cutri |first1=Roc M. |last2=Skrutskie |first2=Michael F. |last3=Van Dyk |first3=Schuyler D. |last4=Beichman |first4=Charles A. |last5=Carpenter |first5=John M. |last6=Chester |first6=Thomas |last7=Cambresy |first7=Laurent |last8=Evans |first8=Tracey E. |last9=Fowler |first9=John W. |last10=Gizis |first10=John E. |last11=Howard |first11=Elizabeth V. |last12=Huchra |first12=John P. |last13=Jarrett |first13=Thomas H. |last14=Kopan |first14=Eugene L. |last15=Kirkpatrick |first15=J. Davy |last16=Light |first16=Robert M. |last17=Marsh |first17=Kenneth A. |last18=McCallon |first18=Howard L. |last19=Schneider |first19=Stephen E. |last20=Stiening |first20=Rae |last21=Sykes |first21=Matthew J. |last22=Weinberg |first22=Martin D. |last23=Wheaton |first23=William A. |last24=Wheelock |first24=Sherry L. |last25=Zacarias |first25=N. |year=2003 |url=http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=II/246 }}</ref>

<ref name=evans>{{Cite journal |title=The VLT-FLAMES Tarantula Survey. I. Introduction and observational overview |journal=Astronomy & Astrophysics |last1=Evans |first1=C. J. |last2=Taylor |first2=W. D. |last3=Hénault-Brunet |first3=V. |last4=Sana |first4=H. |last5=De Koter |first5=A. |last6=Simón-Díaz |first6=S. |last7=Carraro |first7=G. |last8=Bagnoli |first8=T. |last9=Bastian |first9=N. |last10=Bestenlehner |first10=J. M. |last11=Bonanos |first11=A. Z. |last12=Bressert |first12=E. |last13=Brott |first13=I. |last14=Campbell |first14=M. A. |last15=Cantiello |first15=M. |last16=Clark |first16=J. S. |last17=Costa |first17=E. |last18=Crowther |first18=P. A. |last19=De Mink |first19=S. E.|author19-link= Selma de Mink |last20=Doran |first20=E. |last21=Dufton |first21=P. L. |last22=Dunstall |first22=P. R. |last23=Friedrich |first23=K. |last24=Garcia |first24=M. |last25=Gieles |first25=M. |last26=Gräfener |first26=G. |last27=Herrero |first27=A. |last28=Howarth |first28=I. D. |last29=Izzard |first29=R. G. |last30=Langer |first30=N. |last31=Lennon |first31=D. J. |last32=Maíz Apellániz |first32=J. |last33=Markova |first33=N. |last34=Najarro |first34=F. |last35=Puls |first35=J. |last36=Ramirez |first36=O. H. |last37=Sabín-Sanjulián |first37=C. |last38=Smartt |first38=S. J. |last39=Stroud |first39=V. E. |last40=van Loon |first40=J. Th. |last41=Vink |first41=J. S. |last42=Walborn |first42=N. R. |display-authors=5 |volume=530 |pages=A108 |date=June 2011 |doi=10.1051/0004-6361/201116782 |bibcode=2011A&A...530A.108E |arxiv=1103.5386|s2cid=54501763 }}</ref>

<ref name=bressert>{{Cite journal |title=The VLT-FLAMES Tarantula Survey. IV. Candidates for isolated high-mass star formation in 30 Doradus |journal=Astronomy & Astrophysics |last1=Bressert |first1=E. |last2=Bastian |first2=N. |last3=Evans |first3=C. J. |last4=Sana |first4=H. |last5=Hénault-Brunet |first5=V. |last6=Goodwin |first6=S. P. |last7=Parker |first7=R. J. |last8=Gieles |first8=M. |last9=Bestenlehner |first9=J. M.| last10 = Vink | first10 = J. S. |last11=Taylor |first11=W. D. |last12=Crowther |first12=P. A. |last13=Longmore |first13=S. N. |last14=Gräfener |first14=G. |last15=Maíz Apellániz |first15=J. |last16=De Koter |first16=A. |last17=Cantiello |first17=M. |last18=Kruijssen |first18=J. M. D. |display-authors=5 |volume=542 |pages=A49 |date=June 2012 |doi=10.1051/0004-6361/201117247 |bibcode=2012A&A...542A..49B |arxiv=1204.3628|s2cid=73666622 }}</ref>

<ref name=parker>{{cite journal|bibcode= 1992PASP..104.1107P|title= 30 Doradus in the Large Magellanic Cloud: The Stellar Content and Initial Mass Function|journal= Publications of the Astronomical Society of the Pacific|volume= 104|pages= 1107|last1= Parker|first1= Joel Wm.|year= 1992|doi= 10.1086/133097|doi-access= free}}</ref>

<ref name=VFTS682>{{cite journal |title=The VLT-FLAMES Tarantula Survey. III. A very massive star in apparent isolation from the massive cluster R136 |journal=Astronomy & Astrophysics |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. |display-authors=5 |volume=530 |pages=L14 |date=June 2011 |doi=10.1051/0004-6361/201117043 |arxiv=1105.1775 |bibcode=2011A&A...530L..14B|s2cid=119305523 }}</ref>

<ref name=hyland>{{cite journal|bibcode= 1992MNRAS.257..391H |title= Star formation in the Magellanic Clouds. IV - Protostars in the vicinity of 30 Doradus |journal= Monthly Notices of the Royal Astronomical Society |issn=0035-8711 |volume= 257 |issue= 3 |pages= 391 |last1= Hyland |first1= A. R. |last2= Straw |first2= Steven |last3= Jones |first3= T. J. |last4= Gatley |first4= Ian |year= 1992 |doi= 10.1093/mnras/257.3.391 |doi-access= free }}</ref>

<ref name=griendl>{{cite journal|bibcode=2009ApJS..184..172G|title=High- and Intermediate-Mass Young Stellar Objects in the Large Magellanic Cloud|journal=The Astrophysical Journal Supplement|volume=184|issue=1|pages=172|last1=Gruendl|first1=Robert A.|last2=Chu|first2=You-Hua|year=2009|doi=10.1088/0067-0049/184/1/172|arxiv = 0908.0347 |s2cid=18913261}}</ref>

<ref name=banerjee>{{Cite journal |title=Runaway Massive Stars from R136: VFTS 682 is Very Likely a "Slow Runaway" |journal=The Astrophysical Journal |volume=746 |issue=1 |pages=15 |date=February 2012 |last1=Banerjee |first1=S. |last2=Kroupa |first2=P. |last3=Oh |first3=S. |doi=10.1088/0004-637X/746/1/15 |bibcode=2012ApJ...746...15B |arxiv=1111.0291|s2cid=117959362 }}</ref>

<ref name=yusof>{{cite journal |title=Evolution and fate of very massive stars |journal=Monthly Notices of the Royal Astronomical Society |last1=Yusof |first1=N. |last2=Hirschi |first2=R. |last3=Meynet |first3=G. |last4=Crowther |first4=P. A. |last5=Ekstrom |first5=S. |last6=Frischknecht |first6=U. |last7=Georgy |first7=C. |last8=Abu Kassim |first8=H. |last9=Schnurr |first9=O. |display-authors=5 |volume=433 |issue=2 |pages=1114 |date=August 2013 |doi=10.1093/mnras/stt794 |bibcode=2013MNRAS.433.1114Y |arxiv=1305.2099|s2cid=26170005 }}</ref>

<ref name=kohler>{{cite journal |title=The evolution of rotating very massive stars with LMC composition |journal=Astronomy & Astrophysics |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. |display-authors=5 |volume=573 |pages=A71 |date=January 2015 |doi=10.1051/0004-6361/201424356 |bibcode=2015A&A...573A..71K |arxiv=1501.03794|s2cid=28962151 }}</ref>

<ref name=schneider>{{cite journal|bibcode=2018Sci...359...69S|title=An excess of massive stars in the local 30 Doradus starburst|journal=Science|volume=359|issue=6371|pages=69–71|last1=Schneider|first1=F. R. N.|last2=Sana|first2=H.|last3=Evans|first3=C. J.|last4=Bestenlehner|first4=J. M.|last5=Castro|first5=N.|last6=Fossati|first6=L.|last7=Gräfener|first7=G.|last8=Langer|first8=N.|last9=Ramírez-Agudelo|first9=O. H.|last10=Sabín-Sanjulián|first10=C.|last11=Simón-Díaz|first11=S.|last12=Tramper|first12=F.|last13=Crowther|first13=P. A.|last14=De Koter|first14=A.|last15=De Mink|first15=S. E.|author15-link= Selma de Mink |last16=Dufton|first16=P. L.|last17=Garcia|first17=M.|last18=Gieles|first18=M.|last19=Hénault-Brunet|first19=V.|last20=Herrero|first20=A.|last21=Izzard|first21=R. G.|last22=Kalari|first22=V.|last23=Lennon|first23=D. J.|last24=Maíz Apellániz|first24=J.|last25=Markova|first25=N.|last26=Najarro|first26=F.|last27=Podsiadlowski|first27=Ph.|last28=Puls|first28=J.|last29=Taylor|first29=W. D.|last30=Van Loon|first30=J. Th.|display-authors=29|year=2018|pmid=29302009|doi=10.1126/science.aan0106|arxiv=1801.03107|s2cid=206658504}}</ref>

}}

{{Stars of Dorado}}

{{DEFAULTSORT:VFTS 682}}
[[Category:Stars in the Large Magellanic Cloud]]
[[Category:Wolf–Rayet stars]]
[[Category:Extragalactic stars]]
[[Category:Large Magellanic Cloud]]
[[Category:2MASS objects|J05385552-6904267]]
[[Category:Tarantula Nebula]]

{{Sourceattribution|VFTS 682}}