Milwaukee Astronomical Society


M45 - Pleiades - Seven Sisters - Open Cluster


Messier 45 (M45) is a very bright naked-eye Open Cluster of stars known by several names including Pleiades, the Seven Sisters and Subaru. It contains 6 stars of magnitude 4 or brighter and another 6 that are magnitude 5. This grouping of stars has been known since prehistoric times and, depending on the culture, appears in several different versions of folklore. M45 actually contains 332 stars and is located in the constellation Taurus. The blue tint around the brightest stars in images of Pleiades is a Reflection Nebula. It is about 440 light years from earth and is approximately 15 light years in diameter. It was mentioned by Homer in 750 BC as well as several other ancient texts.

Location Data
Constellation: Taurus
Right ascension: 3h 47m
Declination: 24° 7′
Distance:  440 ly
Size:  15 ly

Observation Data
Apparent magnitude: 1.6
Apparent size: 110.0' arcmins

The images With Blue Borders were taken using equipment provided by the MAS Observatory
Click on the Image to View It Full Size