APOD 3.2

Pictured above are the two open star clusters of Perseus, h and Chi Persei. The two were possibly discovered in 130 B.C. by Greek astronomer Hipparcos, and was noted by Tycho Brahe. The entire photograph covers about 3.5 degrees of the sky. The clusters are about 7,000 light-years away and are about 13 million years old, likely from the same starting region. The reddish cloud cover comes from ionized hydrogen gas. There is another open cluster in the upper left corner of this photo and may be related to h and Chi Persei.