Messier 45, the Pleiades, is one of the most beautiful and spectacular open clusters in the entire sky. It is located in the constellation of Taurus.

The blue nebulosity that surrounds the cluster is a reflection nebula. Parts of this nebulosity have individual catalog designations. NGC 1432 is the Maia nebula around Maia. NGC 1435 is the reflection nebula around Merope. VdB 23 is the reflection nebula around Alcyone. VdB 20 is the large area of reflection nebulosity around Merope, Electra, Maia, Taygeta and Sterope which includes NGC 1432 and NGC 1435.

The Pleiades are 100 million years old, and are located 391 light-years away according to measurements made by the Hipparcos satellite.

The cluster contains 1,000 stars, of which more than a dozen can be seen with the unaided eye by keen-eyed observers from a dark-sky site.

The bright stars of the Pleiades can easily be seen even from light-polluted locations. Altas and Pleione, at the end of the handle of the dipper asterism, are fairly close together at 5 arcminutes, making their separation a test of sharp vision.

The named members of the Pleiades and their magnitudes: Pleione - 5.2 Atlas - 3.8 Alcyone - 3.0 Merope - 4.3 Electra - 3.8 Celaeno - 5.4 Taygeta - 4.4 Maia - 4.0 Sterope - 5.9

Known since antiquity, and famous in the sky mythology of most cultures, M45 is also known as the Seven Sisters. The sisters are Sterope, Merope, Electra, Maia, Taygeta, Celaeno, and Alcyone. Their parents are the stars Atlas and Pleione.

North is up in the above image.

Messier 45 Catalogs: M45, Mel 22 Common Name: Pleiades, Seven Sisters, Subaru Object Type: Cluster with Nebulosity Magnitude: 1.2 Size: 100' Constellation: Taurus Image Field Centered At: RA: 03h 46m 59s Dec: +24° 08' 04"