M13: M13, the Great Cluster in Hercules, is probably the most prominent globular cluster visible from the northern hemisphere, overall about magnitude 5.9 and hence visible with binoculars. This was the first deep sky object I found star hopping with my old telescope. Estimates of the number of stars in M13 vary from 100,000 to over a million, in a diameter of about 150 light years across, and is about 20,000 light years from Earth. Globular clusters are among the oldest objects in the galaxy; M13 is over 12 billion years old.

Technical Information:

LRGB: 2:2:2:4 (L, R and G were two one-minute images; B was two two-minute images; L unbinned, R, G and B binned 2x2).

Equipment: 10" LX200 at f/4.6, and an SBIG ST-7E camera/CFW-8 color filter wheel

Image Acquisition/Camera Control: CCDSoft V5 Beta 13.

Processing: All images calibrated (darks only) and registered in AIP4WIN. All layers sum combined in CCDSoft. Luminance layer run through DDP AIP4WIN. Color combine, and adjustment of curves and levels, performed in Photoshop 5.5.

Location: My back yard in Bellevue, Washington, elevation 600'.

Date: All images taken during the night of 5/21/01.