M92

I took an hour of total exposure of this beautiful globular cluster. M92 is one of the brighter globular clusters in the northern hemisphere, but it is often overlooked by amateur astronomers because of its proximity to the even more spectacular Messier 13. It is visible to the naked eye under very good conditions.

It was discovered by Johann Elert Bode in 1777, then published in the Jahrbuch during 1779. The cluster was independently rediscovered by Charles Messier on March 18, 1781 and added as the 92nd entry in his catalogue. M92 is at a distance of about 26,700 light-years away from Earth and has a magnitude of 6.5.

Exposure of this image is:
                          L             =   10 * 180"
                          RGB       =     5 * 120"
                          TOTAL   =    1 hr

Full size in Astrobin