Thursday, March 28, 2013

The Big Dipper - Rutila Major (my bad Latin translation)

For the next few weeks we will be focusing on the northern sky and the stars that are up most of the year. This is a great time to find the Big Dipper. The seven unmistakable stars hang high in the northwest after sunset (upside-down). If you locate a dipper which one is it? Big or Little? If you live in or near a city - no need to fear. You can only see the Big Dipper. Four of the seven stars of the Little Dipper are too faint to see in a light polluted sky.

Different cultures imagined quite different pictures in these stars. In medieval Europe it was a death cart or wagon. Some Native American groups called it the "Thigh of an Ox" while others used it as a eye test (see if you can see an extra star hovering just above one of the seven). Egyptians called it a coffin. African Americans called it the "Drinking Gourd". In England they still call it The Plow.

Here is a very famous painting by Vincent van Gogh called "Starry Night over the Rhone". It's pretty obvious where the Big Dipper is. Van Gogh included stars in several of his paintings including Starry Night and Cafe Terrace at Night.
If you have trouble seeing any of those things in the Big Dipper, try to modernize it. Maybe to you it will look like a lawn mower, shopping cart, or question mark. Don't ask me why that shopping cart is in a jacuzzi...

Monday, March 4, 2013

Canis Major and Canis Minor, Orion's Sky Dogs

Sirius A and B
The winter southern sky is ablaze with the brightest stars in the sky.  8 of the top 20 brightest stars can be found there awaiting your wishes.  The brightest of them all is Sirius, the nose of Orion's bigger hunting dog, Canis Major.  Sirius is about 23 times brighter than the North Star and scorches the winter sky with a stark white light.  Sirius definitely isn't the biggest star up there - it's just one of the closest.  At about 8.6 light years away, it's really two stars - a faint white dwarf star called Sirius B orbits the main star every 50 years.

Creepy Lookin' Dogs
Up higher and not quite as bright is the little dog star, Procyon.  Procyon weighs in as the eighth brightest star in the sky becuase it's a close one too.  In fact Procyon bears a lot of similarities with Sirius.  At about 11 light years away, this white sub-giant star has a white dwarf star orbiting it as well.

Canis Major, is easy to find.  Use Orion’s belt as a guide.  Connect the dots of the three belt stars and continue the line down and to the left and you will run smack into Sirius.  With a little imagination you can use the semi-bright stars around Sirius to picture the big dog, but with the little dog… it only has two stars in it.  That’s right, it’s a real hot dog!