The brightest star of the rabbit is a member of a rare class. It’s a yellow supergiant – a star that’s about the same color as the Sun, but much bigger and brighter. It won’t stay in that class for long, though. It’ll quickly get hotter and bluer, then blast itself to bits as a supernova.

Arneb is the leading light of the constellation Lepus, the hare. It’s in the southeast at nightfall, to the lower right of brilliant Orion. Its name is Arabic for hare – a name that also represented the whole constellation.

Arneb is about a dozen times the mass of the Sun, perhaps a hundred times its diameter, and tens of thousands of times its brightness.

The star is about 13 million years old – compared to four and a half billion years for the Sun. But because of its great mass, Arneb has already completed the main phase of life. Changes in its core caused it to puff up to become a red supergiant.

Now, it’s getting smaller, which is making its surface hotter. As part of that transition, it’s turned yellow. But it won’t stay that color for long. As it continues to contract, it’ll get even hotter, so its surface will turn blue. And within a couple of million years, Arneb will explode. That will leave only a small, superdense core – a neutron star. It’ll be surrounded by an expanding cloud of debris that will shine for millennia – the final act of a rare and mighty star.

We’ll have more about the rabbit tomorrow.

Script by Damond Benningfield