Pleiades Cluster

From Memory Alpha, the free Star Trek reference

The Pleiades Cluster (also known as M45 or the Seven Sisters) is a star cluster, located around 425 light years from Sol, which contains hundreds of stars and many young planets. The Alcyone system and Velara III are among the locations in or near this cluster.

An image appearing to be this cluster was contained in the Enterprise computer in 2254, when the Talosians scanned Enterprise's records. (TOS: "The Cage")

On Stardate 41463.9 the USS Enterprise-D was on a mission to map these new planets found in the Pleiades Cluster. (TNG: "Home Soil")

While on a date, on a holographic recreation of Mars, with Denara Pel, The Doctor pointed out the Pleiades Cluster as among the many star formations and astronomical highlights seen from Mars. (VOY: "Lifesigns")