M21
M21 is one of the youngest of the open clusters in our Milky Way, estimated to be only about 4 ½ million years old. While its distance is not accurately known, it is undoubtedly relatively nearby, probably about 3,000 light-years. The cluster is quite densely populated in the center and thus appears to be a single bright star surrounded by a few fainter ones in small instruments but the actual group membership is about 50 stars. Time exposures reveal the rich background of more distant suns.
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Image taken August 21, 2009, with the C-14 operating at F:7 The ST-8 was binned 2 X 2 and exposed for 5 minutes |