Universe Today
Chandrasekhar limit
1.4 solar masses: the most a white dwarf can weigh before it cannot hold itself up.
Subrahmanyan Chandrasekhar worked it out at nineteen, on a boat to England, and was publicly ridiculed for it by the most eminent astrophysicist of the day. He was right. Above about 1.4 solar masses the electron pressure holding a white dwarf up fails, and the star either detonates as a Type Ia supernova or collapses further into a neutron star. Because the threshold is the same everywhere the explosions are near-identical in brightness, which is what makes them the standard candles that revealed dark energy.
Where it has come up lately
Related terms
Magnetar
A neutron star with a magnetic field a thousand trillion times Earth's.
Supernova (Type Ia and Type II)
Two unrelated ways for a star to explode, useful for two entirely different reasons.
The main sequence
The long, stable middle age a star spends fusing hydrogen in its core.
Hertzsprung–Russell diagram
The single plot that organises everything about stars.
Questions
What is Chandrasekhar limit?
1.4 solar masses: the most a white dwarf can weigh before it cannot hold itself up.
Why does it matter?
Above about 1.4 solar masses the electron pressure holding a white dwarf up fails, and the star either detonates as a Type Ia supernova or collapses further into a neutron star. Because the threshold is the same everywhere the explosions are near-identical in brightness, which is what makes them the standard candles that revealed dark energy.