The open star clusters M 6 (upper right) and M 7 (lower left) in the
constellation of
Scorpius are a
fine pair already visible by naked eye. They lie in between of dense
star and dust clouds of the summer milky way.
See also:
Jean-Claude Mermilliod's open cluster compilations on
M 6
and M 7
Woldemar Götz, "Die offenen Sternhaufen unserer Galaxis", VEB Johann Ambrosius Barth, Leipzig