Star Clusters - celestialpixels
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Ptolemy Cluster - M7

Ptolemy Cluster - M7

M7 is one of the most prominent open clusters of stars on the sky. The cluster, dominated by bright blue stars, can be seen with the naked eye in a dark sky in the tail of the constellation of the Scorpion (Scorpius). M7 contains about 100 stars in total, is about 200 million years old, spans 25 light-years across, and lies about 1000 light-years away. M7 has been known since antiquity; it was first recorded by the 1st-century Greek-Roman astronomer Ptolemy, who described it as a nebula in 130 AD.[5] Italian astronomer Giovanni Batista Hodierna observed it before 1654 and counted 30 stars in it. In 1764, French astronomer Charles Messier catalogued the cluster as the seventh member in his list of comet-like objects

Telescope: OS RH200
Camera: ATIK383L+
Mount: AP Mach1 GTO
Filters: Baader LRGB
Location: Mt. Parnon
Total exposure: 4h

m7ptolemycluster