Western Slope Skies 7/5/2013

While there are always objects of interest to see in the night sky throughout the year, the summer sky is unique in that it offers us a view into the very center of the Milky Way, our home galaxy.

Two constellations in the direction of the Milky Way’s center are Scorpius and Sagittarius.  If you can find a dark area with a good view to the south, you should be able to pick out the constellation, Scorpius, the Scorpion.  It is one of the few constellations that looks like its name.  The tail is quite distinctive, looping down close to the horizon and then back up with two stars marking the stinger.

The bright, red-orange star in the middle of Scorpius is Antares.  It is called the heart of the scorpion, because of its color and location in the constellation.  Antares is a red super-giant, which is old age for a star.  If it were located where our sun is, the Earth and even Mars would be inside the star.

Just to the east of Scorpius is Sagittarius.  Central to Sagittarius is an asterism called “The Teapot”.  It consists of 8 stars that form the handle, base, spout, and top of a teapot. 

The center of our galaxy is just to the west and north of the tip of the spout, where a supermassive black hole exists.  The Milky Way black hole has a mass of about 4  million Suns.  Present theory is that most galaxies have a large black hole at their center. 

The center is about 26,000 light years from Earth. The closest star to the black hole is called S0-102 and it orbits at 11 million miles per hour!

Many star clusters and nebulae are concentrated around the Milky Way’s center.  So, on clear and dark summer night, it is quite easy to observe 30 - 40 of these deep sky objects before midnight. You will have all summer to observe the center of the Milky Way.  Remember to use dark nights with no moon.