Jimmy Westlake: ‘The Great Overdog’
December 16, 2007
American poet Robert Frost was a poet of the stars. Just listen to his short poem about Orion’s big hunting dog entitled “Canis Major”:
“The great Overdog
That Heavenly beast
With a star in one eye
Gives a leap in the east.
He dances upright
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All the way to the west
And never once drops
On his forefeet to rest.
I’m a poor underdog,
But tonight I will bark
With the great Overdog
That romps through the dark!”
What a thrill it is to see the Great Overdog poke his nose over our mountains as he gives his leap in the east! His nose is marked by no less than the brightest star visible in our night sky, the dazzling white superstar Sirius, also nicknamed the Dog Star. When Sirius suddenly breaks over the mountain, it’s as if a miniature sun has risen, casting faint, flickering shadows over the snowy ground. When seen low on the horizon, Sirius seems to flicker and flash with every color of the rainbow!
About 40 times more luminous than our sun, Sirius is the sixth closest star to our solar system, lying a mere 8.6 light years away. The bright star that we see is actually accompanied by a fainter companion star that we can’t see without a powerful telescope. Called Sirius B, it was the first white dwarf star to be discovered.
Just south of Sirius is the beautiful star cluster called M41. It is faintly visible to the unaided eye on a clear, dark night, but M41 is resolved into a jewel box of diamonds and sapphires with just a simple pair of binoculars. It’s hard to believe that the glittering starlight from this cluster of stars began its journey to Earth 2200 years ago!
You can locate the rising point of Sirius by following a line through the three stars of Orion’s belt down to the southeast horizon. You’ll know when Sirius is about to the crest the mountain peaks when you spot the fainter star Mirzam rising in the same location. Mirzam means “the Announcer,” so named because it heralds the impending appearance of the Dog Star, Sirius.
Sirius rises at about 8:00 p.m. on Christmas Eve, and about 30 minutes earlier, or 7:30 p.m., on New Years Eve. Why not step outside with your family this holiday season and bark with “the Great Overdog that romps through the dark?”
Professor Jimmy Westlake teaches astronomy and physics at Colorado Mountain College’s Alpine Campus. He is an avid astronomer whose photographs and articles have been published on the websites of CNN.com, NASA’s “Astronomy Picture of the Day” website, Spaceweather.com, Space.com, Discover.com, MSNBC.com, NationalGeographic.com, and in Sky & Telescope, Astronomy, Night Sky, Discover, and WeatherWise magazines. His “Celestial News” article appears weekly in the Steamboat Pilot newspaper. His “Cosmic Moment” radio spots can be heard on local radio station KFMU.