Jimmy Westlake: Orion rising
November 24, 2009
Steamboat Springs — "You know, Orion always comes up sideways,
Throwing a leg up over our fence of mountains,
And, rising on his hands, he looks in on me …"
This excerpt from Robert Frost's poem, "The Star Splitter," captures in words one of my favorite celestial events: the rising of the magnificent constellation of Orion the Hunter.
All of a sudden, after changing from daylight saving time to standard time at the beginning of November, Orion is rising in the early evening before most of us go to bed instead of around midnight. You can catch him "throwing his leg up over our fence of mountains" in the eastern sky at about 8 p.m. in late November.
Orion is one of only two constellations visible from Colorado that contains two first-magnitude stars. Ruddy Betelgeuse marks his shoulder, and icy-blue Rigel marks his foot. Both stars pop up over the mountains at about the same time, followed immediately by the three stars of Orion's Belt: Alnitak, Alnilam, and Mintaka. The three belt-stars rise in a vertical column, halfway between Betelgeuse and Rigel, almost like one of Orion's arrows shot straight up from below the horizon.
Hanging from Orion's Belt is his sword, composed of a fainter triplet of stars. The middle star in the sword looks fuzzy, even to the naked eye. This is the Great Orion Nebula, also known by its Messier catalog number, M42. Aim your binoculars or telescope at Orion's sword for a closer view of one of the largest hydrogen gas clouds in the Milky Way. Dozens of new solar systems are forming in this stellar nursery, nearly 1,500 light years from Earth.
Greek mythology tells us the great hunter Orion once boasted that he could kill every living creature on Earth, if he wanted to. The animals of the forest got together and decided they must make a preemptive strike, just in case Orion was serious. They chose one of their smallest members, the scorpion, to teach Orion a deadly lesson. Stalking the hunter one day in the woods, the scorpion stung Orion on the heel. The great hunter wheeled around in pain and collapsed from the scorpion's fatal poison. The scorpion and the hunter were immortalized in the stars as our constellations of Scorpius and Orion, but they were placed on opposite sides of the sky so that the two mortal enemies never could be seen together. Orion rides high in the mid-winter sky, and Scorpius appears low in our mid-summer sky.
When you see Orion rising in the early evening, you can be certain the winter snows are not far behind.
Welcome back, old friend.
Professor Jimmy Westlake teaches astronomy and physics at Colorado Mountain College's Alpine Campus. He is an avid astronomer whose photographs and articles have been published all around the world. His "Celestial News" column appears weekly in the Steamboat Pilot newspaper. His "Cosmic Moment" radio spots can be heard on local radio station KFMU. Also, check out Jimmy's website at http://www.jwestlake.com.