Question

What is the mass and size of a white dwarf?

Answer 1

Mass of the Sun, size of the Earth.

Explanation:

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`.

https://www.google.com.pk/search?q=Sirius+B&biw=1600&bih=799&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiztaGoxfPJAhUQhhoKHSPdDXUQ_AUIBigB#imgrc=FpZY2AOns-__BM%3A