Moondark for December: Old Friend Orion

Seeing Orion always brings a smile to my face. It never fails: like an old friend, this constellation is instantly recognizable, a rectangle with three stars set aslant across the middle. On edge near the horizon, or even upside down from south of the equator, its sight marks the turn of the seasons. From my backyard, it rises with the chill of the early winter and sets as the warm nights of summer approach.

Stargazers know Orion well. The Hunter has the most first-magnitude stars of any constellation. The spectacular Great Orion Nebula (also know as Messier 42) is a cinch to find as the middle “star” in the Sword. Who hasn’t enjoyed their "first light" in a brand new telescope with M42? Or tested optics on the Trapezium multiple star system?

This is a colorful constellation. Betelgeuse, his right shoulder, shines distinctly orange. Through a large telescope, the delicate detail visible in M42 is bathed in a blue-green fluorescent glow that rivals any photograph. There is much to challenge the observer as well, including emission nebulae like the Flame (NGC 2024), reflection nebulae like M78, elusive dark nebulae like the Horsehead (B33), and even a few faint galaxies like NGC 1924, scarcely 2° west of M42. With the nearest spiral arm of our Milky Way passing just off his shoulder, there are plenty more double stars, open and globular star clusters, and glowing gas clouds nearby.

Even those new to the hobby recognize Orion. After the Big Dipper, it seems to be the second constellation many folks learn. It surely helps that the stars, bright and dim, do outline a human form. There is a rich and ancient mythology surrounding this constellation, variously known as a hunter, warrior, king or other heroic figure. What we call the Belt and the Sword is inverted down-under and called the Pot and the Laddle. Do you remember Orion’s necklace from the blockbuster movie Men in Black? The Hubble Space Telescope has revealed numerous new planets and stars caught in the act of forming in the midst of the Great Orion Nebula. Are these stellar nurseries destined to be solar systems like ours?

Whether with a new eyepiece found under the Christmas tree, an old pair of binoculars or just your eyes and a hot drink, I hope you enjoy Orion as much as I do. So with warm wishes for clear, cold Orion-filled skies, Happy Holidays!

Image info: top right: Orion, a lunar halo in high cirrus clouds and a cottonwood tree, 35-mm camera on tripod; middle left: M42, the Great Orion Nebula, imaged with a 80-mm refractor and CCD camera; middle right, Orion and the adjacent Winter Milky Way, 35-mm tracked photo; and bottom left, to show star and nebular colors, serially defocused photograph, 35-mm camera on tripod. *** Moondark is written by Doug Miller and published on the web and in the Delmarva Star Gazers'Star Gazer News. Please address comments and suggestions to dcmiller@dmv.com. This document was last revised on 25 November '00. All text and images copyright © 2000 Douglas C. Miller, All Rights Reserved. This material may not be reproduced in any form without prior permission.