What is the mass and size of a white dwarf?

1 Answer
Dec 24, 2015

Mass of the Sun, size of the Earth.


A White dwarf is the left over core from the death of a normal sized Star like our Sun. A white dwarf has typically the mass of the Sun but is about the same size as the Earth so small and extremely massive.

Take an example of Sirius B. Sirius B is a White dwarf at about 10 light-years from the Sun. Its about the same mass as the Sun about 2 Solar Masses (2 x #10^30# kg) but is even smaller than the size of the Earth and extremely hot about 25000 K. The Radius of Sirius B is about 5800 km whereas, the radius of the Earth is about 6400 km. The density of Sirius B is about 2 x #10^9# kg#m^-3#.

enter image source here