... The Pleiades star cluster is one of the jewels of the northern sky. To the unaided eye it appears as an alluring group of stars in the constellation Taurus, while telescopic views reveal cluster stars surrounded by delicate blue wisps of dust-reflected starlight. Chandras First Light: Cassiopeia A . ... Located 4000 light years away in the disk of our Galaxy, NGC 6188 is home to the Ara OB1 association, a group of bright young stars whose nucleus forms the open cluster NGC 6193. ...