Archive for October, 2009

Three Clusters in Auriga

Friday, October 23rd, 2009

Why look at one star cluster when you can see three of them? In the constellation Auriga, now showing up in the East around midnight, three moderately bright, but densely packed open clusters line up very nicely. The stars of Auriga are quite bright, so the pattern of the constellation should be easily visible. In the right side of that pattern, a line of stars (circled in yellow on the map) is faintly visible to the naked eye, and easy to spot through a finder scope. Follow the line of these stars to the left, and very quickly you’ll come to the first of these clusters, M38. Once you’ve found M38, start scanning down and you’ll find the other two clusters, first M36 and then M37. All three clusters are between magnitude 5.6 and 6.4 in brightness, with a large number of stars making each a telescopic treat.

0025clust

The Orionids

Sunday, October 11th, 2009

These nights, if you stay up late enough, the easily recognisable  constellation Orion is visible. And on October 21-22, this constellation is the radiant of the annual Orionid meteor shower. While the Orionids aren’t one of the better known meteor showers, everyone has heard of the comet that creates them. It’s none other than the famous Halley’s Comet. The rate of meteors is quite small for this shower, about 10 to 15 per hour. But it is known to sometimes produce spectacular fireballs. And the good news is that this year the moon shouldn’t cause any problems with viewing.

Wile E. Coyote Hired by NASA!

Thursday, October 8th, 2009

Well, not really. After all, despite being a self-described super-genius, good ‘ol Wile E. is a coyote … and fictional. But still, if the cartoon canine somehow could take over a NASA mission, and if he somehow suspected the Road Runner was on the moon, the result would probably be something along the lines of what’s going to happen Friday morning. Starting at about 7:31 a.m. EDT, NASA will continue it’s “let’s smash stuff open and see what’s inside” method of exploration by having it’s LCROSS mission impact the moon, not just once, but twice. First the LCROSS (Lunar Crater Observation Sensing Satellite) will separate from the empty Centaur rocket stage that helped send it on it’s mission. The rocket stage will be sent crashing into the lunar crater Cabeus. The LCROSS itself will be close behind, first monitoring the results of the Centaur impact, then impacting itself. The purpose of all this is to look for signs of water ice near the lunar south pole. Such a find could be a great boon to future manned moon missions. If you have a backyard scope ten inches or larger in diameter, you may be able to see the debris plume kicked up by the impacts yourself.  Check out this SPACE.com article for more information on when and where to look.

Bull’s Eye!

Thursday, October 8th, 2009
Head of the Bull

Now that we’ve made the turn from summer to autumn, a familiar array of nighttime sights are returning to view. Two of the most famous are the constellation Orion and the Pleiades star cluster. And right between the two is the almost as famous star Aldebaran. Also known as Alpha Tauri, it is one of the brightest stars in the night sky. In the consteallation Taurus, the brightest stars of the Hyades cluster form a large V shape known as the “head” of the bull. Aldebaran, while not actually part of the Hyades cluster, lies in the same line of sight. With it’s bright red glow, it’s often called the “Bull’s Eye.” While the Hyades is the nearest open cluster to Earth, at a distance of about 151 light years, Aldebaran is even closer. It’s distance of only 65 light years, combined with a luminosity 150 times that of the sun, yields a bright apparent magnitude of 0.85.

The influence of early Arab astronomers is shown in the large number of star names that come from Arabic. The name Aldebaran is taken from the Arabic “al-dabarān” (meaning “the follower”) for the way the star “follows” the Pleiades. However the star was also famous among ancient Persians, Chinese and many others.  And the best part of following in the steps of these ancient astonomers and observing Aldebaran and the Hyades is no equipment is required. Just go outside on an autumn night, face east, and look up. These naked eye sights are a great way to get an easy (and free) introduction to astronomy.