Messier 3 (also known as M3 or NGC 5272) is a globular cluster in the constellation Canes Venatici. It was discovered by Charles Messier in 1764, and resolved into stars by William Herschel around 1784. This cluster is one of the largest and brightest, and is made up of around 500,000 stars. It is located at a distance of about 33,900 light-years away from Earth. M3 has an apparent magnitude of 6.2, making it visible to the naked eye under dark conditions. From a moderate-sized telescope, the cluster is fully defined. It is estimated to be 8 billion years old.

http://en.wikipedia.org/wiki/Messier_3

ABOUT THE IMAGE

DATE/TIME:  The evening of April 4th, 2010

CAMERA:  Canon XSI, 450D

TELESCOPE:  Orion 100mm ED refractor @ F/18

ISO SETTING:  800

EXPOSURES:  18

EXPOSURE LENGTH:  100sec

TOTAL EXPOSURE LENGTH:  30min.

SUBTRACTIONS:  10 darkframes, 10 bias frames

CAPTURE SOFTWARE:  MaximDL

STACKING SOFTWARE:  Deep Sky Stacker

PROCESSING:  Photoshop CS3