The July/August 2016 issue of Discover Magazine has an apparently paper-only issue on astromical Thorne–Żytkow objects (TZOs), of which I’d never heard. From Wikipedia:
A Thorne–Żytkow object is formed when a neutron star collides with a star, typically a red giant or supergiant. The colliding objects can simply be wandering stars. This is only likely to occur in extremely crowded globular clusters. Alternatively, the neutron star could form in abinary system after one of the two stars went supernova. Because no supernova is perfectly symmetric, and because the binding energy of the binary changes with the mass lost in the supernova, the neutron star will be left with some velocity relative to its original orbit. This kick may cause its new orbit to intersect with its companion, or, if its companion is a main-sequence star, it may be engulfed when its companion evolves into a red giant.
I boggle at the thought. And now some in the astronomy community believe the star known as HV 2112 may be the first known example of these objects. SciNews covered the initial announcement more than two years ago here.
When they took a close look at the subtle lines in the spectrum of HV 2112, they found that it contained excess rubidium, lithium and molybdenum.
Past research has shown that normal stellar processes can create each of these elements. But high abundances of all three of these at the temperatures typical of red supergiants is a unique signature of TZOs.
“I am extremely happy that observational confirmation of our theoretical prediction has started to emerge,” said Dr Zytkow from the University of Cambridge, who is a co-author of the paper accepted for publication in the Monthly Notices of the Royal Astronomical Society Letters (arXiv.org version).
Look at your smartphone. Odds are that some of its components were first created within a TZO.
