Whats Up In the Sky April 07
In the early morning April Sky the constellation Hercules rides high bringing with it one of the most spectacular objects in the northern hemisphere, M13. M13, the great globular cluster, is estimated to have 400,000 stars packed into an area of 140 light years of space. Star density is estimated to be only a few A.U. apart. If the sun were located in M13, there would be thousands of stars within the distance that we now have seperating us and Alpha Centauri.
Astronomers are using globular clusters to help date the age of the Milky Way. Globular clusters contain some of the oldest stars in the Milky Way. Their stars contain small amounts of chemicals that have been synthesized in an earlier generation of massive stars that exploded as supernovae after a short and energetic life. That material formed into clouds that formed the next generation of stars. Less massive stars have not been found. Our conclusion is the Milky Way galaxy is older than globular clusters. The stars in globular clusters are estimated to be 13,000 milion years old. The Milky Way is estimated to be around 13,600 million years old.
M13 was the first object to have radio signals beamed at it from Arecibo, Puerto Rico, with the hope that some other civilization would reply. A reply we will have to wait on for 50,000 years. Let’s hope there is still a civilization to hear the reply, and that they can understand it.
M13 should be called Halley’s Cluster. Edmond Halley, of comet fame, discovered the cluster in 1714. This is the same cluster that we associate with Charles Messier who cataloged it in 1764 as M13. Halley is an interesting person, among his accomplishments he developed the actuary tables used by insurance companies to determine average life span and what to charge you for insurance at the age you are now.
If you can’t do early morning astronomy, M13 will be back in the evening sky late June and eary July.
As for April 07 look for:
2 The full moon will be the smallest of the year.
7 The moon occults Antares for New Zealand and eastern Australia. In the dawn sky look for the Moon, Jupiter and the bright star Antares in
the SSW in close proximity till the ninth.
13- 14 At dawn the Moon and Mars low in the ESE.
18-20 Sunset, the Moon, Venus, the Pleiades and Hyades in close proximity
22- 25 the Moon will move from Gemini to Leo coming close to Saturn on the twentyfourth.
