Click here for a review of the strengths and weaknesses of the Global Rent-A-Scope operation.
This image was created by median combining 7 x 30 second images using B, V and R filters taken with a Takahashi Epsilon 250 with SBIG ST-8XE CCD. The image has been cut down to be 20 x 20 arc minutes in size.
M21 (NGC 6531) is an open cluster with a strong concentration of stars toward its centre. M21 is a very young cluster with an estimated age of 4.6 million years and is part of the Sagittarius OB1 stellar association.
In collaboration with the Remote Astronomical Society Observatory
Martin Nicholson - Daventry, United Kingdom.
This page was last updated on April 15th 2009.