M45: The Pleiades

This very bright open cluster has a large angular extent, making it a great binocular object. If you viewed this object through a large telescope, you would only see a few stars, not the entire cluster. Perhaps the most famous open cluster, this is easily visible with the naked eye. In fact, many children with great eyesight look toward this cluster and mistake it for the Little Dipper. When you view this cluster through binoculars, it does in fact look like a measuring cup.M45, or the Pleiades, or the Seven Sisters, or Subaru if you're in Japan, are all names for this cluster. In Greek mythology, the Seven Sisters were the daughters of Atlas and Pleione, and the half-sisters of Hyades. It is interesting to note that when counting the brightest stars in this cluster, most people only come up with six. Some versions of the mythology describe a missing sister, the reason why we do not see a seventh bright star is unknown.The bright blue, massive stars that make up this cluster are less than 100 million years old.

This image was taken as part of Advanced Observing Program (AOP) program at Kitt Peak Visitor Center during 2014.