Final answer:
Subrahmanyan Chandrasekhar, an Indian-American astrophysicist, discovered the mass limit for white dwarfs, known as the Chandrasekhar limit, which is approximately 1.4 times the mass of the Sun.
Step-by-step explanation:
The mass limit for white dwarfs was discovered by the Indian-American astrophysicist Subrahmanyan Chandrasekhar. He found that as the mass of a white dwarf increases, its radius decreases until it reaches a theoretical zero at a mass of roughly 1.4 times that of the Sun. This mass limit is known as the Chandrasekhar limit and represents the maximum mass a star can have and still become a white dwarf; any star with a greater end-of-life mass is expected to undergo a different, more violent end. Chandrasekhar's groundbreaking work unveiled the role of electron degeneracy pressure in stabilizing white dwarfs, a state referred to as a degenerate gas. This pressure arises due to the Pauli exclusion principle, which states no two electrons can occupy the same quantum state simultaneously. However, Chandrasekhar showed that electron degeneracy pressure is not sufficient to stave off the collapse if a white dwarf's mass exceeds the Chandrasekhar limit. Chandrasekhar's findings initially met with skepticism and opposition from prominent astronomers of his time, such as Sir Arthur Eddington. Despite this, his work laid the foundation for much of our modern understanding of end-of-life stellar evolution.