A type Ia supernova occurs when a white dwarf — the cooling remnant of an aging star — draws hydrogen from a companion sun. When the dwarf reaches 1.4 times the mass of the Sun, the star ...

When they reach the end of their long evolutions, smaller stars—those up to eight times as massive as our own ... like our own sun. The brightest star in the nighttime sky, Sirius, or the ...

Sirius B takes roughly 50 years to orbit Sirius A. At their nearest approach, the stars are still some 7 astronomical units (AU) from each other, or seven times the Earth-Sun distance. (One AU is ...