Looking Up: Head in the Clouds

Dec 5, 2016

Credit Rogelio Bernal Andreo / NASA.gov

This week on Looking Up Hal takes us inside the head of the hunter (Orion).

Heads up, everyone! Today let’s talk about a head that’s up. And by up, I mean a star visible in the southern Colorado sky right now, and by heads I mean the remarkable star that makes up the head of the wonderful constellation of Orion the Hunter.

Orion is almost certainly the most famous winter constellation, dominating a large portion of the night sky, and containing a number of very bright stars, including Betelgeuse, Rigel, and Saiph, which we which we discussed in earlier episodes. Those three stars, along with Bellatrix, which we’ll talk about in a future episode, make up the “body,” so to speak, of Orion. But have you ever looked at his head? And by head, I mean the very cool star, Meissa! And this cool star is very, very hot!

Perched between the “shoulder stars” of Betelgeuse and Bellatrix, Meissa is a class O giant star, at least 25 times bigger than our Sun. It burns at a temperature of over 62,000°F, compared our own Sun’s measly 10,000°F. It’s also 65,000 times brighter than our Sun, so let’s be glad that it’s 1100 light years away. Meissa is actually the big brother in a multiple star system, but the companion stars are too dim to see with the naked eye.

But what makes Meissa so interesting to astronomers is not so much the star itself, but what’s around it. Meissa is surrounded by a huge ring of gas, cleverly named the “Meissa Ring.” Hey, I never said astronomers were witty. And this ring of gas is an amazing 150 LIGHT YEARS across. And that ring appears to be surrounded by an even LARGER ring of interstellar dust and debris. We’re not sure if those rings are left over from Meissa’s formation, or if it might be material left over from a nearby star exploding. You might say, but probably shouldln’t, that it’s a real Mess-a out there.

If you’d like to take a closer look at Meissa, 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! 

This is Hal Bidlack for the Colorado Springs Astronomical Society, telling you to keep looking up, Southern Colorado!