 M7, (NGC6475) This open cluster is sometimes called Ptolemy's cluster because the first description we have of the open cluster is from the second century C.E. (formerly A.D.) Claudius Ptolemaeus, who described it as a fuzzy patch following the scorpion's stinger. The fuzzy patch resolves into stars in binoculars. Dreyer calls it very bright (mag. 3.3), pretty rich with stars of roughly 7-12 mag. It covers about 1.3° of the sky.
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M NGC Con RA Dec Mag Size (min) Typ Distance Common Name --- ---- --- ------- ------ ---- ---------- --- -------- ------------- 7 6475 Sco 17 53.9 -34 49 3.5 80.0 OCl 1 Ptolemy's Cluster |