Ptolemy discovered M 7 in Scorpius about 130 BC. He published the observation in his work Almagest. Halley re-discovered the open cluster in 1678.

D N NI Y I T Observer Name Con Type S Author Title
1 N 6475 -130? E v Halley 1678
Lacaille 15.6.1752
M 7, Ptolemy's Cluster SCO II2r 4 Ptolemy Almagest