Draft:Sirius B

Sirius B is a white dwarf, a remnant of an intermediate-mass star that have end its life, being the closest example to Earth. Like all white dwarfs, Sirius B is massive and dense: While its size is comparable to that of Earth, its mass is equivalent to that of the Sun. It is the progenitor of a 5 M_☉ star that existed around 100 million years ago.

It is the secondary object of the Sirius system, of which the 'A' component is the brightest star in the night sky. Sirius B, on the other hand, can't be seen to the naked eye, as its luminosity is only 2% that of the Sun. They share a orbit 40 astronomical units wide and need 50 years to complete one orbit.

Introduction

White dwarfs are remnants of intermediate-mass stars which have end their lifes. The Sun is expected to become a white dwarf as well. Such objects do not produce energy via nuclear fusion and cool over time. Sirius B is young and has a hot surface temperature at around 25,000 degrees, compared to the 5,778 K (5,505 °C) of the Sun. The electron degeneracy pressure make these objects dense, so a white dwarf can be as massive as the Sun while its radius is comparable to Earth.