This Vast Neutron Star Shocked Scientists With Its Size

This hefty neutron star has a grizzly story, as it is devouring material from its nearby binary partner. It is a type called a black widow neutron star, named after the spiders which eat their mates. In astronomical terms, this object has shredded its nearby stellar companion through the forces of gravity and consumed its matter, feeding on it (via W.M. Keck Observatory).

The companion star in this system is now just 20 times the mass of Jupiter, which is very small by stellar standards, and its shape has been distorted by the mass of the nearby neutron star. It is also tidally locked to the neutron star, meaning one side always faces it, and the temperatures on this side are over 10,000 degrees Fahrenheit. That’s hotter than our sun, which makes it possible to see the desiccated star through telescopes even though it’s small.

Studying these black widow neutron stars which grow to very large masses can help researchers learn about the limit at which a neutron star turns into a black hole. The researchers that were a part of this most recent set of findings have suggested that the recently identified object could be close to that limit already, and that they won’t likely find any neutron stars which are more massive.

“We can keep looking for black widows and similar neutron stars that skate even closer to the black hole brink,” Filippenko said. “But if we don’t find any, it tightens the argument that 2.3 solar masses is the true limit, beyond which they become black holes.”