Red supergiant may have a neutron star at its core

Ars Technica : The first Thorne–Zytkow Object (TZO) may have been found by Anna Zytkow of Cambridge University and her colleagues. In the 1970s Zytkow, working with theoretical astrophysicist Kip Thorne, predicted that in some binary systems, one star could go supernova and leave behind a neutron star that was close enough to its partner to merge with it and replace the partner star’s core. The heat from the neutron star would offset its gravitational pull, resulting in a stable star, albeit with differences that could be detected via spectroscopy. After analyzing 62 red supergiants in the Milky Way and the Large and Small Magellanic Clouds, the researchers found one star that was a significant outlier from the group. The star HV 2112 matched many, but not all, of the theory’s predictions. Zytkow suggests that the predictions themselves need to be reworked based on information about stars that has been learned since the theory was developed, and that once updated, the predictions may be more in line with the observations.