Nearly half a century ago, physicist Kip Thorne (now a Nobel laureate) and astronomer Anna Żytkow suggested a strange, Russian-nesting-doll-type star might be hiding in the cosmos, just waiting to be found by those who knew how to seek it. Astronomers named these theoretical stellar hybrids Thorne-Żytkow objects.
The possible existence of Thorne-Żytkow objects came to light when their namesake researchers ran early computer simulations. When they did, they found that a neutron star — a tiny, ultra-dense stellar remnant left behind when a star goes supernova — could be gobbled up by a red supergiant star.
According to the simulations, if the “Twins” (in the Danny DeVito-Arnold Schwarzenegger sense) get too close to one another, instead of one star getting ejected, the two stars can merge together. The city-sized, solar-mass neutron star would carry on living inside its much larger host, almost like a cosmic parasite.
