And now, for your viewing pleasure ...
Wednesday, July 16, 2014
Here we are, almost in the middle of summer. The nights are getting longer -- a little bit at a time, but definitely longer, and some of the most exciting astronomical objects are available for our viewing pleasure.
Our old friends in the Summer Triangle (Vega, Deneb, and Altair) are in great position above the eastern horizon about an hour after local sunset; The Big and Little Dippers and their crew are in the north, and Sagittarius and Scorpius, two more traditional summer constellation are in prime viewing position in the south.
But probably the most "target rich" environments is the summer Milky Way, the starry edge of our home galaxy. It is that bright band of stars and star clusters and nebula stretching from the south, directly overhead into the north.
The best viewing place for a walk along that astral river is your favorite dark sky place, the darker the better away for all artificial lighting. We used to say "city lights," but any more artificial lighting is reaching out into the country.
The best thing about viewing the Milky Way is you don't really need a telescope, just your eyes and a good pair of binoculars.
Let's start in the south, right in the middle of Sagittarius and Scorpius. That area contains the center of our galaxy, and the many globular star clusters and glowing, gaseous nebula that orbit it.
Look for the giant "J" of Scorpius hanging due south anytime after the sky gets good and dark, usually about 9:00 pm local time.
It's tail with the two-star "stinger" dipping into the southern end of the Milky Way.
Just above the stinger are two nice open star clusters. I should probably insert a note here about the difference between an open star cluster and a globular cluster.
An open cluster is just that, open and spread out while the globular cluster has a bright, thick heart of many hundreds of stars all crowded together.
The lower cluster just above the scorpion's stinger are Ptolemy's Cluster (M7), the other cluster is the Butterfly Cluster, M6. If you look at it with your binoculars, you will see why it is called a butterfly.
The "M" designation refers to the list compiled by the French comet hunter, Charles Messier, of things which were not comets.
Right next door to the left is Sagittarius. While normally called an archer, the more modern way of looking at the mythological Centaur is as a common tea pot with a looped handle on the right, a triangular top and another triangle on the right side as a spout.
It appears as if the Milky Way is the steam coming out of the tea pot's spout, and right in the middle of that steam just above the spout is the center our galaxy.
It is bright with the light of millions and millions of stars but we are not able to see it due to all the inter-stellar dust and molecular clouds between us and there. The only way to see it is using infrared telescope photography.
SKYWATCH: Third quarter moon, Friday, July 18.
NEXT WEEK: The Trifid, the Lagoon, the Eagle and more astronomical blathering.