A Giant Constellation: Orion
February 2002 :
One of those bright and easily recognizable constellations is Orion, the mighty hunter. Though one does not need a telescope to view all the stars that comprise this star pattern, you can put your Christmas telescope to good use and go outside this February and focus your attention on one of the most beautiful celestial objects that resides within Orion's starry boundaries.
Orion is easy to identify, not only because it is the most prominent star pattern in the winter sky, but also because it is the brightest of all the constellations. And during February around 8:00 pm, Orion can be found about halfway above the southern horizon. Though Orion rises on his side, only when he is due south of our location is he standing upright. With the exception of the Big Dipper (Ursa Major) and Scorpius, Orion is probably the most recognizable of star patterns.
The prominent red star Betelgeuse marks Orion's eastern shoulder and Bellatrix marks the western one. Betelgeuse, which means "the armpit of the central one," is a red giant star. It coincidentally resides in a "giant" of a constellation. If Betelgeuse occupied the position of our Sun, it would extend outward toward the orbit of Mars.
Blue-white Rigel is positioned at Orion's western heel, while Saiph is at the east one. Rigel, in Arabic, means "the left leg of the giant." West of Bellatrix is a curved group of eight stars that represents Orion's shield. Contained within the rectangle formed by Betelgeuse, Bellatrix, Rigel and Saiph is a string of three stars that comprises Orion's belt. Just below the belt you'll find Orion's sword, made up of a small group of stars.
The grandeur of Orion resides in the region of his sword. Using binoculars you'll see a wispy, hazy patch of green light enshrouding the stars. Using a telescope even under low magnification will reveal a greenish tinged nebula of dust and gas--the magnificent Orion Nebula.
You'll be amazed at the intricate swirls of nebulosity, especially on a moon-less night in a dark country sky. You'll also immediately notice four bright stars embedded in the nebulosity. This asterism is called the Trapezium. These four stars are "youngsters" in the universe. They formed out of some of the gas and dust in the Great Nebula. Other suns will also coalesce out of this stellar nursery in the future.
No one has described the humbling effect the Orion Nebula has on us amateur astronomers any better than Garrett P. Serviss in his 1901 book Pleasures of the Telescope.
Nowhere else in the heavens is the architecture of a nebula so clearly displayed.... The work of creation is proceeding within its precincts. There are stars apparently completed, shining like gems just dropped from the hand of the polisher, and around them are masses, eddies, currents, and swirls of nebulous matter yet to be condensed, compacted, and constructed into suns. It is an education in the nebular theory of the universe merely to look at this spot with a good telescope. If we do not gaze at it long and wistfully, and return to it many times with unflagging interest, we may be certain that there is not the making of an astronomer in us.As I write this column during mid-January the weather has been absolutely lousy, with one storm system after another. I hope this pattern changes during February so nightly star patterns will replace nightly weather patterns. Even if the temperatures dip below freezing, put those telescopes to good use collecting photons of light from many distant realms in the heavens. Make your first target the Orion Nebula and determine for yourself whether or not Serviss's description does justice to the magnificence of this Great Nebula.
The Great Orion Nebula looks absolutely wonderful with some of the larger instruments at Seagrave Memorial Observatory on Peeptoad Road in North Scituate. So visit us, weather permitting of course, on any Saturday night. Our members will be happy to share their love of the sky with you. (If you have 3 or 4 inches of snow and ice in your backyard, our parking lot is most likely inaccessible and the observatory will be closed.) More information, including directions and membership, can be found at our new website: www.theskyscrapers.org
Next month I'll write about the current viewing season for Jupiter and Saturn before they disappear into the Sun's glare in late April. Start looking now if a clear night presents you with a good viewing window of opportunity. Jupiter is the brightest object high in the eastern sky sitting amongst the stars of Gemini, while Saturn is dimmer, but higher still, near the v-shaped group of stars forming part of Taurus the Bull.
