What is a cannibal star?

Answer 1

A cannibal star is a star that is close enough to another stellar object, where it can "feed" off it's companion.

This maybe a white dwarf and it's stellar rich star or a hydrogen filled planet, that has strayed too close and its matter is "sucked" into the star.

Because of the Chandrasekhar Limit, a Feeding Star in a binary system can consume as much mass from its companion as 1.44m (m is the mass of our sun) before it turns into a type 1a supernova. These supernova are very easy to discern among other novae because they are all the same brightness and have the same chemical composition and thus can be used as a standard candle to judge the distances to other galaxies. However in an observed type 1a supernova in 2006, the mass of the white dwarf exceeded 2m before it went supernova because of centrifugal force (how fast it spins). This observation challenges the idea of using type 1a supernova as standard candles.

Answer 2

A cannibal star is a star that consumes material from a neighboring star or stars in a binary star system. This can happen when one star expands and begins to transfer material onto the other star through their gravitational interaction. This process can significantly impact the evolution of both stars.