Pleiades Star Cluster

The Pleiades Star Cluster, also known as M45 was one of the first objects that I indexed for my Messier catalog project. Yet, it is worth another mention in this blog for several reasons: First, it is a great deep sky object for any amateur to locate - easily found in the Constellation Taurus, M45 is probably one of the most famous and visible open clusters in the winter sky. A bright grouping of stars in the early night sky, it is a great deep sky object to share with children and or friends that may not normally be into observational astronomy. It is comprised of approx. 7 primary stars which is where it gets the ancient nickname of the "Seven Sisters", according to Greek Mythology. It is best seen using a 45mm eye piece or even binoculars. The cluster is actually comprised of up to 500 stars which are better seen by zooming in with a 10mm eye piece. With a magnitude of 1.20 it is easily spotted with the naked eye as a dense grouping of stars in the night sky.

M45 is approximately 400 light years from Earth and it is certainly more mentionable now as the astronomy community celebrates the 2009 International Year of Astronomy. It was 4o0 years ago that Galileo took the first look up at Pleiades through what is considered the first ever telescope. The light from that view 400 years ago is just now reaching earth which makes this star cluster worth mentioning again.

Interestingly, there is blue reflection nebulosity associated with this object that can be seen only with a longer exposed image. This is a great object to sketch and then later go back and research and label the primary 7 stars. Even as I search for objects in the magnitude range of 10-13 mag., I am always drawn back to M45 as it is always a worthwhile object to gaze upon.