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Originally Posted by ESO 19 Nov 2018\
The VISIR instrument on ESO’s Very Large Telescope has captured a
stunning image of a newly discovered massive triple star system. Nicknamed Apep after an ancient Egyptian deity, this may be the first ever gamma-ray burst progenitor found.
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These stellar winds have created the elaborate plumes surrounding the triple star system — which consists of a binary star system and a companion single star bound together by gravity. Though only two star-like objects are visible in the image, the lower source is in fact an unresolved binary Wolf-Rayet star. This binary is responsible for sculpting the serpentine swirls surrounding Apep, which are formed in the wake of the colliding stellar winds from the two Wolf-Rayet stars.
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Originally Posted by ESO
Compared to the extraordinary speed of Apep’s winds, the dust pinwheel itself swirls outwards at a leisurely pace, “crawling” along at less than 2 million km/h. The wild discrepancy between the speed of Apep’s rapid stellar winds and that of the unhurried dust pinwheel is thought to result from one of the stars in the binary launching both a fast and a slow wind — in different directions.
This would imply that the star is undergoing near-critical rotation — that is, rotating so fast that it is nearly ripping itself apart. A Wolf-Rayet star with such rapid rotation is believed to produce a long-duration GRB when its core collapses at the end of its life.
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ESO press release and image here :-
https://www.eso.org/public/news/eso1838/
Thankfully we won't be in the death zone for the GRB, despite it being only 8000 ly distant.
Article in Sydney Morning Herald :-
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Originally Posted by Liam Mannix, Sydney Morning Herald
"Luckily," says Professor Peter Tuthill, an astronomer at the University of Sydney who was part of the team that studied the dangerous stars, "this one isn’t pointed to us at all – it won’t be coming our way."
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https://www.smh.com.au/national/supe...19-p50gyy.html
Nature Astronomy article (subscription or purchase required).
"Anisotropic winds in a Wolf–Rayet binary identify a potential gamma-ray burst progenitor" by Callingham et. al.
https://www.nature.com/articles/s41550-018-0617-7
