As such, Sirius B's redshift provided supportive evidence of an important prediction of Einstein's General Theory of Relativity. Sirius B has another claim to fame. This white dwarf star fueled a debate in the 1920s between leading astrophysicists Subrahmanyan Chandrasekhar and Sir Authur Eddington. Chandrasekhar derived a relation ship between the star's mass and its radius which sets an upper limit to the mass a white dwarf can have, beyond which it will collapse to a neutron star or, if sufficiently massive, to a black hole. Decades later Chandrasekhar's fundamental contributions were recognized when he won the 1983 Nobel Prize in Physics.
More massive stars tend to burn hotter and faster.
Once all the nuclear fuel has been exhausted, such stars quickly collapse, shedding much of their mass in dramatic explosions called supernovae . The most recent event of this kind was observed in 1987 when a star weighing the equivalent of 20 suns blew up in a neighboring galaxy 160,000 light years away. If after such an explosion, the remaining material is greater than 1.4 solar masses, it will contract into an unimaginably dense core made solely of neutrons. Eventually astronomers may discover the telltale signs of a neutron star exactly where the old star met its doom, though as yet none has been detected. As heavy as neutron stars are, if they're less than 2 solar masses, they too can only contract so far and no further.