May 25, 2015 09:57 PM
(This post was last modified: May 25, 2015 10:16 PM by Yazata.)
The Astronomy world is talking about a peculiar one-of-a kind star that astronomers call 'Nasty 1' (from its catalog name 'NaSt 1'. 'Na' and 'St' are the first two letters of its discoverers' names).
It's a Wolf-Reyet star, a peculiar exceedingly-bright kind of star that's missing its outer hydrogen atmosphere, partially exposing the hydrogen fusion underneath. As large stars with more than 20x solar mass age, their hydrogen atmosphere expands, so that it begins to be lost into space. Apparently these unstable W-R stars sometimes are the earlier stages of what become supernovae and collapsars (stars that contract into black holes), so they generate lots of astrophysical interest.
It now appears that multiple processes may be at work in their formation.
Nasty 1 is different from other W-R stars observed in that a disk of gas is visible around it. Astronomers hypothesize that there's another star in there, a close binary, whose gravity is stripping off the massive star's loose hydrogen. The astrophysicists who are proposing this think that the stripping process doesn't take very long at all in astronomical terms, maybe 100,000 years. So it's just chance that we are able to see it underway in this example.
So the new idea seems to be that some of the W-R stars at least might be binaries, where one of the two expands past a certain point and gets fed upon by its cannibal twin.
http://astronomynow.com/2015/05/24/hubbl...ed-nasty1/
http://en.wikipedia.org/wiki/Wolf–Rayet_star
It's a Wolf-Reyet star, a peculiar exceedingly-bright kind of star that's missing its outer hydrogen atmosphere, partially exposing the hydrogen fusion underneath. As large stars with more than 20x solar mass age, their hydrogen atmosphere expands, so that it begins to be lost into space. Apparently these unstable W-R stars sometimes are the earlier stages of what become supernovae and collapsars (stars that contract into black holes), so they generate lots of astrophysical interest.
It now appears that multiple processes may be at work in their formation.
Nasty 1 is different from other W-R stars observed in that a disk of gas is visible around it. Astronomers hypothesize that there's another star in there, a close binary, whose gravity is stripping off the massive star's loose hydrogen. The astrophysicists who are proposing this think that the stripping process doesn't take very long at all in astronomical terms, maybe 100,000 years. So it's just chance that we are able to see it underway in this example.
So the new idea seems to be that some of the W-R stars at least might be binaries, where one of the two expands past a certain point and gets fed upon by its cannibal twin.
http://astronomynow.com/2015/05/24/hubbl...ed-nasty1/
http://en.wikipedia.org/wiki/Wolf–Rayet_star
