The Constellation Orion

Orion is perhaps the most famous of the 88 constellations in the night sky.  It’s likely the easiest to find for stargazers all over the world.  And unlike most constellations, Orion looks like its legendary namesake: a mighty hunter with a shield, a raised arm, and a sword hanging from his star-jeweled belt.

This time of year, for northern observers, Orion is primed for viewing moderately high in the southeastern sky about 9 p.m.  Southern observers enjoy the striking sight of Orion “upside down”, high overhead in the summer sky.

Here’s a map to show you what Orion looks like, and how to find which of its stars is which…

The constellation Orion (click to enlarge)

After three decades of stargazing, I’m still awestruck by the splendour of this constellation on a cold winter’s night.  No amount of observation dulls Orion’s beauty.  Glittering like a gigantic piece of celestial jewelry, it holds a number of the brightest stars in the sky.  Many of these stars formed in the great Orion star factory, an invisible mass of gas and dust that’s even now condensing into new stars.

The bright red-orange star marking Orion’s shoulder is called Betelguese (“BAY-tell-jewz”).  It’s a massive star that’s burned through most of its fuel, and will explode as a supernova that shines so bright, it will cast shadows by night and and be visible in our daytime for several weeks.  This explosion may happen next year, or in a million years.  No one knows for sure.

The brighter of the two blue-white stars marking Orion’s feet is Rigel (“RYE-jel”).  It’s much younger than Betelguese, and slightly brighter (only five stars in the entire sky outshine Rigel).  In a large backyard telescope, keen-eyed observers will notice Rigel has a faint companion star which is called Rigel B.

Three stars lined up in a tidy row mark Orion’s Belt.  These stars are Alnitak, Alnilam, and Mintaka.  The stars lie almost exactly on the celestial equator, an imaginary line encircling the sky which lies directly above the Earth’s equator.

Look closely at the group of three dim stars that appear to hang off the belt.  The middle star appears fuzzy and indistinct, because it’s entangled in a mass of glowing gas and dust called the Orion Nebula where a cluster of brand-new stars are in the process of formation.  You can learn more about the nebula here…

That’s enough for today.  When you have a little time, go have a good look at Orion.  It’s a favorite constellation of many experienced stargazers.