Spot one of the greatest sights in the winter sky – Orion
By Chris Fellows, Serenity Mobile Observatory
Winter is upon us and for those who have the fortitude and constitution it brings a treat that amateur astronomers wait all year for. The mighty Orion Nebula blazes so brightly that most mistake if for a star, but even through very modest telescopes or decent binoculars this is a sprawling nebula with fantastic structure and beauty. In this article, I will show you how to find M42 and give some observing tips to help you better enjoy the spectacle.
First, let’s find this baby in the sky. Orion is one of the most recognizable constellations. Second only to Ursa Major (The Big Dipper), almost everyone can spot Orion the hunter. At this time of year, only an hour or so after dark, Orion will be climbing over the eastern horizon with his distinctive seven very bright stars that make up the hunter’s shoulders, belt and feet. Prominent stars in this constellation are Rigel, his left foot, and Betelgeuse (pronounced beetle juice), his right shoulder.
Just look east after dark and you won’t be able to miss Orion. Now look a little closer. Hanging from his belt, most people will be able to see three additional “stars” that make up Orion’s club. The middle star in this group isn’t a star at all but a giant molecular cloud of hydrogen gas and dust. It glows brightly because of the four super massive, hot young stars at its center called the Trapezium. According to Wikipedia “The Trapezium is a component of the much larger Orion Nebula Cluster, an association of about 2,800 stars within a diameter of 20 light years.” And “Charles Messier first noted the nebula on March 4, 1769, and he also noted three of the stars in Trapezium. Messier published the first edition of his catalog of deep sky objects in 1774 (completed in 1771). As the Orion Nebula was the 42nd object in his list, it became identified as M42.”
Under long exposure photography the Orion nebula bursts into color: pinks and reds of hydrogen gas that is lit up, like a neon tube, by the energy of the young hot stars at its core; blue reflection nebula bouncing off the dusty remnants of interstellar material; and a strange green tinge that baffled scientists until late in the 20th century, when the experimentalists helped the observers figure out that it was a rare electron interaction in vacuum conditions.
When observing Orion, use your telescope’s wide field eyepieces to get the best and sharpest views. I normally reach for a 24 mm at dark sky locations or a 13 mm if there is some sky glow so I can concentrate on the core area. Averted vision (see earlier article) will help pull out structure and detail at the eyepiece. Most importantly, take your time, make sure you are fully dark adapted (30 minutes out in the dark), and enjoy the views.
Till next time …
Chris Fellows, Serenity Mobile Observatory
Find Chris on Facebook (or, if you’re lucky, at your campground). (Editor: Check out his amazing photos on his Facebook page!)