Winter brings out the big dogs – some of the most prominent constellations of all. And one of those really is a dog: Canis Major, the big dog. It’s best known for Sirius, the Dog Star – the brightest star in the night sky. It’s a third of the way up the southern sky at nightfall.

But there’s much more to Canis Major than just Sirius. It includes several bright stars, most of which are below or to the right of Sirius. When you link them up, they do form the outline of a dog.

Like all constellations, Canis Major consists of more than just a connect-the-dots pattern of stars, though. It covers a patch of sky that includes everything within its borders. And in that area, you can find several deep-sky objects – objects like star clusters, which are far beyond most of the individual stars visible in Canis Major.

Perhaps the best known is Messier 41. It’s not far below Sirius, and it’s an easy target for binoculars. It’s about 2300 light-years away, and includes a hundred or more stars.

The cluster probably is about 200 million years old. At that age, its biggest, heaviest stars have expired. They’ve left behind small, dense corpses known as white dwarfs. The next-heaviest stars soon will follow the same path. Those stars have puffed up to become red giants. They’re easily visible through binoculars – sparkling red and orange jewels along the “collar” of the big dog.

More about Canis Major tomorrow.

Script by Damond Benningfield