APOD
Astronomy Picture of the Day
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
The M7 Open Star Cluster in Scorpius
Explanation: M7 is one of the most prominent open clusters of stars on the sky. The cluster, dominated by bright blue stars , can be seen with the naked eye in a dark sky in the tail of the constellation of Scorpius . M7 contains about 100 stars in total, is about 200 million years old, spans 25 light-years across, and lies about 1000 light-years away. This color picture was taken recently at the Kitt Peak National Observatory in Arizona , USA as part of the Advanced Observers Program . The M7 star cluster has been known since ancient times, being noted by Ptolemy in the year 130 AD. Also visible is a dark dust cloud near the bottom of the frame, and literally millions of unrelated stars towards the Galactic center .
| Date | April 6, 2005 |
|---|---|
| Credit | Credit & Copyright: Allan Cook & Adam Block , NOAO , AURA , NSF |
| Authors & editors: | Robert Nemiroff (MTU) & Jerry Bonnell (UMCP) |
| A service of: |
ASD at NASA / GSFC, NASA Science Activation & Michigan Tech. U. |



