Viewing the Summer Triangle, Saturn
Thursday, July 7, 2011
Our old friends, the stars of the Summer Triangle, are above the eastern horizon by 9 p.m. and a planet, Saturn, is available for our viewing pleasure.
Saturn is located in the constellation Virgo, the Maiden located along the southern horizon. There are two bight objects in Virgo, one is Saturn and to its left is Spica, the brightest star in the constellation.
A telescope will give a fine view of the ringed planet. The rings are still opening up after their minimum last year.
Saturn is still near the star Porrima, the pair can be seen in binoculars.
To help find Spica use the arc in the handle of the Big Dipper. Follow it around and down and "arc" to the star Arcturus in Bootes then "speed-on" to Spica in Virgo.
There are other old friends in the mid-evening skies. The quintessential summer constellations Scorpius, the Scorpion and Sagittarius, the Centaur are in the south at about 10 p.m. local time.
First Scorpius. Although it appears as a fierce beast, there are several delightful astronomical objects to be found here.
Below the three stars marking the head is very bright Antares, the heart of the critter. Antares, the "Rival of Mars." Both Mars and Antares have a similar reddish glow in the sky and when they are near a good comparison can be made.
If you look just to the right of Antares in the same binocular field of view you will find a very nice little globular star cluster, M4, called "The Cat's Eye."
Follow the body of the scorpion down toward the horizon and just where the line takes a jag right, look for a superb example of an open star cluster with the rather drab name of NGC 6231.
I call it a jewel box. Not, however, to be confused with the real Jewel Box cluster in the southern hemisphere. It consists of hundreds of stars of many colors. A grand sight in binoculars, overwhelming in a telescope.
Continue to follow the line of the scorpion's body to the tip of the tail, to "The Stinger." In fact, that is what that star is called. Shalula, Arabic for "The Sting." The star just next to it is called Lesath.
Shaula is a multiple-star system, Lesath is not one of them.
Now, one more look while we are in the area. Move your binoculars up and just a bit left of Shaula to find two open star clusters almost in the same field of view.
The one to the left of Shaula, is M7, Ptolemy's Cluster, so named for the ancient astronomer who recorded seeing it 2,000 years ago.
Above and slightly right is M6, the Butterfly Cluster. Why? Well, just look at it and you will understand.
Sky Watch Next Week: Sagittarius and more astronomical blathering.