View source for Astronomy:W75N(B)-VLA2

{{Starbox begin |
   name=W75N(B)-VLA2}}
{{Starbox observe
 |epoch=J2000
  |ra={{RA|20|38|36.482}}<ref name=CarrascoGonzalez/>
  | dec={{DEC|+42|37|34.09}}<ref name=CarrascoGonzalez/>
  |constell=[[Astronomy:Cygnus (constellation)|Cygnus]] }}
{{Starbox character
  |class=Be }}
{{Starbox detail 
 |mass=~9<ref name=physorg/>
 |luminosity=300 }}
{{Starbox reference
 |Simbad=%5BTGR97%5D+VLA+2}}
{{Starbox end}}
[[Image:VLA images of W75N(B)-VLA-2.jpg|thumb|260px|W75N(B)-VLA2 in 1996 (top) and in 2014]]

'''W75N(B)-VLA2''' is a massive [[Astronomy:Protostar|protostar]] located in the [[Astronomy:Cygnus X (star complex)|Cygnus X]] region
some 4,200 light-years from Earth, about 8 times more massive<ref name=physorg>[http://phys.org/news/2015-04-vla-images-years-difference-young.html phys.org: VLA images 18 years apart show dramatic difference in young stellar system, 2 April 2015]</ref> and 300 times brighter than the [[Astronomy:Sun|Sun]], observed in 1996 and 2014 by the Karl G. Jansky Very Large Array (VLA). In 2014 its [[Astronomy:Stellar wind|stellar wind]] had changed from a compact spherical form to a larger thermal, ionized  elliptical one outlining collimated motion,  giving critical insight into the very early stages of the formation of a massive star.<ref name=CarrascoGonzalez>{{Cite journal | doi = 10.1126/science.aaa7216| title = Observing the onset of outflow collimation in a massive protostar| journal = Science| volume = 348| issue = 6230| pages = 114–7| year = 2015| last1 = Carrasco-Gonzalez | first1 = C.| last2 = Torrelles | first2 = J. M.| last3 = Canto | first3 = J.| last4 = Curiel | first4 = S.| last5 = Surcis | first5 = G.| last6 = Vlemmings | first6 = W. H. T.| last7 = Van Langevelde | first7 = H. J.| last8 = Goddi | first8 = C.| last9 = Anglada | first9 = G.| last10 = Kim | first10 = S. - W. | last11 = Kim | first11 = J. - S. | last12 = Gomez | first12 = J. F. | pmid=25838383|arxiv = 1507.05285 |bibcode = 2015Sci...348..114C | s2cid = 206635741}}</ref><ref>[https://www.bbc.co.uk/news/science-environment-32168507 BBC News: Star's birth glimpsed 'in real time', 3 April 2015]</ref> Being able to observe its rapid growth as it happens (in [[Social:Real time (media)|real time]] in an astronomical context) is unique, according to Huib van Langevelde of [[Organization:Leiden University|Leiden University]], one of the authors of a study of the [[Astronomy:Astronomical object|object]].

The authors of the study believe W75N(B)-VLA2 is forming in a dense, gaseous environment, surrounded by a dusty torus. The star intermittently ejects a hot, ionized wind for several years. Initially the wind can expand in all directions and forms a spherical shell; later it hits the dusty torus, which slows it. There is less resistance along the poles of the torus, so the wind moves more quickly there, giving rise to an elongated shape.<ref name=physorg/>

==References==
{{Reflist}}

{{Stars of Cygnus}}

[[Category:Cygnus (constellation)]]
[[Category:Protostars]]


{{Sourceattribution|W75N(B)-VLA2}}