Due to its great brilliancy and richness, the great French astronomy popularizer Camille Flammarion was fond of calling the winter constellation Orion the "California of the Sky." Aside from the Big Dipper itself, perhaps no other star grouping in the entire heavens is as well known. And it’s at its glorious best on February evenings.
As the brightest of the 88 constellations in the sky, Orion is unmistakable. Simply going outside on a clear winter’s night and looking up, your gaze is immediately riveted on its display of colorful bright stars. The first thing you’ll notice are its two brightest luminaries, Betelgeuse and Rigel. If you think stars don’t have color, think again! The former is a red giant super sun and glows a distinct deep orange in hue. The latter is a blue giant and sparkles like a brilliant celestial diamond.
Next, notice its distinctive line of three "belt stars" lying diagonally midway between the above two super-suns. This distinctive group is officially known as an "asterism" (which we have discussed in previous columns). Following the line downward (southeast) in the sky brings you to the brightest star in the entire heavens, Sirius in Canis Major (the Big Dog). Going upward (northwest) in the opposite direction points you first to the V-shaped Hyades star cluster and beyond it the dipper-shaped misty stellar jewel box called the Pleiades—both of which lie in Taurus, the Bull. Little wonder that Orion and its surroundings have always been so captivating to even the most casual sky watcher.
But the most observed and famous attraction of Orion is the magnificent Orion Nebula.
You’ll find it in Orion’s "sword" hanging from the easternmost belt-star, its middle star appearing to the unaided eye as a fuzzy spot. It definitely looks nebulous in binoculars and is an awesome sight even in small telescopes. At its core is the amazing Trapezium multiple star appearing like blue-white diamonds set against the emerald-green nebulosity. These are the brightest members of an actual star cluster condensing out of the nebula itself. You are seeing stars being born here right before your eyes!
I’ve viewed the Orion Nebula literally thousands of times over the past 50 years using hundreds of different sizes and types of telescopes—including some of the largest in the world. The views are simply beyond description as telescope size increases. But my favorite one is that seen through the Scientific’s Astroscan-Plus. Its huge 3-degree field of view (that’s 6 Full-Moon diameters of sky!) using its 16 power eyepiece takes in the entire Orion Nebula Complex. This not only consists of the main nebula itself (M 42), its detached northern portion (M43), a sparse open star cluster north of it, and several double stars around and to the south of the nebula. Flammarion was right—here truly is a celestial gold mine in the night sky!
— James Mullaney
Former assistant editor at Sky & Telescope magazine & author of nine books on stargazing. His latest, Celebrating the Universe!, is available from HayHouse.com.