Answer to Question #90283 in Astronomy | Astrophysics for Shivam Nishad

Question

What is a white dwarf star ? Explain, on physical basis the existence of an upper limit on the mass of a white dwarf star. What is this limiting value called ?

Answer 1

A white dwarf star is the last milestone of evolution of stars while its mass is less than the Chandrasekhar limit.

The white dwarfs are very dense since their masses have order of mass of the sun but their size is less than 1% of size of the sun. At such densities electron shells of atoms destroy. If a dwarf has mass higher than the Chandrasekhar limit, the electrons will be so close to protons that they will annihilate to neutrons and the star will become a neutron star.