The Hunter Returns
Like Christmas commercials and college football's big rivalries, Orion, the hunter, always returns to prime time at this time of year. The constellation starts climbing into sight in early evening, and is in full view by about 9 o'clock.
To find Orion, look for his eye-catching belt -- a short line of three fairly bright stars standing straight up from the horizon in the east. The two brightest stars in the constellation line up to the left and right of the belt, roughly parallel to the horizon as they rise. The star to the left is Betelgeuse, while the one on the right is Rigel.
Both stars are supergiants. Betelgeuse looks orange, while Rigel is blue. The different colors mean that the surface of Rigel is thousands of degrees hotter.
Both stars are larger and more massive than the Sun. As a result, they "burn" their nuclear fuel in a hurry, so they produce tremendous amounts of energy in their cores. That makes them big and bright.
But this flashiness carries a price. Rigel and Betelgeuse will live fairly short lives -- in the millions of years, versus billions of years for the smaller, more sedate Sun. And both stars will end their lives with titanic explosions, called supernovae. For a few days or weeks, these exploding stars will outshine all the other stars in the galaxy combined.
For now, though, look for these and the other stars of Orion rolling across the southern sky during the night.
Script by Damond Benningfield, Copyright 2001, 2004, 2008
For more skywatching tips, astronomy news, and much more, read StarDate magazine.