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Yours truly
M 13 (NGC 6205), in Hercules
M13 is the brightest globular cluster in the northern sky. Located in Hercules, it's a magnificent sight in binoculars as well as in a scope. It is large and approximately 22,800 light years distant from Earth. Burnham estimates that the number of stars in this densely packed cluster "cannot be less than a million;" Kepple and Sanner give a figure of "several hundred thousand." If you lived on a planet in a solar system within this cluster, the entire night sky would be filled with stars as bright or brighter than Venus. Spectacular!
CCD (June 2005)
| Date |
2005-06-03 |
| Scope |
RCOS Ritchey-Chretien telescope on an A-P 1200 GTO mount. Camera: SBIG ST-10MXE and CFW color wheel, controlled with MaxIm 4.10 and internal guide chip. |
| Exposure |
R, G, and B exposures 5 x 120 sec with Astrodon filters. |
| Processing |
Calibrated and combined in MaxIm; final processing in Photoshop CS2. |
CCD (July 2003)
This CCD image was grabbed with 3 minute exposures to check unguided performance. Overall, the tracking was adequate although some frames were discarded because of trailing.
| Date |
2003 July 1 |
| Scope |
Astro-Physics 130 EDF at f4.5 AP 1200GTO mount, unguided. Camera: SBIG ST-10MXE and CFW color wheel, controlled with MaxIm |
| Exposure |
R, G, and B exposures 3 x 180 sec. Luminance synthesized by averaging the R, G, and B frames. |
| Processing |
Frames calibrated and RGB combined in MaxIm. The luminance layer was subjected to DDP processing in MaxIm and then 3 iterations of Richardson-Lucy deconvolution in CCDSharp. Final processing with Levels and Curves in Photoshop. The image shown is the cropped central 50% (approximately) of the frame. |
Film Version (Much Older)
| Date | 25 April 2000 |
| Scope |
Astro-Physics 130 EDF at f12 (2x Barlow) on G-11 mount. Guiding with ST-4 on a separate guide scope. |
| Exposure | One 30 min on PPF400 film, no filter |
| Processing | Slight stretching and unsharp mask in Photoshop |