Globular Cluster M13 (NGC 6205), class V, in Hercules

RA 16 : 41.7 (h:m); DEC +36 : 28 (deg:m) ; Distance 25.100 light years;
Visual Brightness 5.8 (mag) ; Apparent Dimension 16.6 (arc min)

M13, also called the `Great globular cluster in Hercules', is one of the most prominent and best known globulars of the Northern celestial hemisphere. It was discovered by Edmond Halley in 1714, who noted that `it shows itself to the naked eye when the sky is serene and the Moon absent.'
At its distance of 25,100 light years, its angular diameter of 23' corresponds to a linear 165 light years. It contains several 100,000 stars ...

Source and more: SEDS


March 31, 2009 22:48 - 23:27 UT.
Imaging: William Optics Zenithstar 80 ED II APO, f/6.8 [focal length 545 mm], Astronomik LRGB Filters; ATK16IC camera.
Exposures: Lum 16x90s [1x1]; RGB 5x45 [2x2]; all unguided.

July 23, 2008 21:10 - 21:31 UT.
Imaging: William Optics Zenithstar 80 ED II APO, f/6.8 [focal length 545 mm], Astronomik LRGB Filters; ATK16IC camera.
Exposures: Lum 5x120s [1x1]; RGB 3x60 [2x2]; all unguided.

July 1, 2006 22:09 - 22:25 UT.
Imaged with LX200 10-inch f/10 telescope with 0.33 Focal Reducer operating at f/4.06 [focal length 1015mm], Vesta Pro-SC3a colour camera, Baader Infra Red Blocking Filter.

July 5, 2004 2248:22:59 UT.
Imaging and processing procedure: see my DSO imaging page.

June 26, 2003 22:39 - 23:10 UT .
TAL-2M 150mm in prime focus @ f/8 and Baader IRB filter, Vesta Pro-SC1.5, used stack 25x20 secs [unguided] exposures.
YRGB processing.