Gamma Cassiopeia is a busy star system. The main star is surrounding itself with a disk of gas and dust. The star is interacting with an invisible companion. And it’s building up to an impressive demise.

Gamma Cas is the middle point of the letter M or W formed by the stars of Cassiopeia, which is high in the north-northwest at nightfall. Gamma Cas is the most distant member of that pattern, at 550 light-years. Its main star – the one visible to the eye alone – is about 15 times the mass of the Sun. And it’s about 20,000 times brighter than the Sun.

The star spins at about a million miles an hour at its equator. That causes it to bulge outward, so it looks more like a lozenge than a ball. That high speed causes the star to fling gas from its surface, forming a disk around the star.

Its companion probably is the corpse of a once mighty star. Some of the gas from the main star may fall onto the companion.

Gamma Cas is only about eight million years old, yet it’s nearing its end. In a few million years more, it’s likely to explode – ending the life of this busy star.

Incidentally, Gamma Cas has another name: Navi. It was bestowed in the 1960s by the crew of Apollo 1. It’s the middle name of commander Virgil Ivan Grissom spelled backward. After the crew died in a launchpad fire, NASA placed Navi on the charts used by later crews to navigate to the Moon.

Script by Damond Benningfield