Looking Up: Just The Cold Hard Facts

Dec 23, 2019

Jupiter was in the midst of the Winter Circle in 2014. Every month the Circle is visible, the moon sweeps through it. Photo by EarthSky Facebook friend Duke Marsh in Indiana.
Credit Duke Marsh / earthsky.org

This week on Looking Up Hal gets around to telling us about an asterism visible in the night sky this time of year - the Winter Circle.

If you are a weather wimp, like I am, you prefer warm weather. That point of view is a bit unfortunate for astronomers, because the winter night sky seen here in Colorado is in many ways far more beautiful and interesting than what we see when it’s warm outside.

That cold fact is amply demonstrated by what astronomers call the Winter Circle, now blazing gloriously in the Colorado night sky. The eight brightest stars in the entire sky are up there in, well, a circle.

Sirius, the brightest of all the stars, starts the circle below and to the left of the wonderful constellation Orion. Continuing the circle, we reach bright stars I’ve told you about in earlier episodes, Rigel, Aldebaran, Capella, Menkalinan, Caster, Pollux, and then Procyon. Each of these stars shines brightly and cover over 60 degrees of the night sky. You can’t really look at the Colorado winter night sky without taking in members of that circle, they are wonderful and interesting. And because they are made up of stars across several constellations, the Winter Circle itself is called an “asterism,” much like the Big Dipper.

So be sure to check out the Winter Circle and spend some time looking at the brightest stars you can see in the sky. They’re wonderful!

If you’d like to take a closer look at the Colorado night sky, or any of the other wonderful and amazing things in the sky, please visit csastro.org for a link to information on our monthly meetings and our free public star parties.