M5 - Globular Cluster Now In Color

(Click image to go to info page)

As described in a previous post found here, the high-resolution (unbinned) luminance data for this showcase globular cluster was captured in early May 2011 from my favorite dark site at the Chiefland Astronomy Village. On my return trip to CAV in June 2011, I collected the low-resolution (binned 2x2) red, green, and blue data. Normally, I adjust the exposure times for each filter per results of manual G2V calibration that I performed when I first acquired the SBIG ST-8300M camera and then use 1/1/1 weighting when color combining. This time I used the same exposure (5-minutes) for each sub-frame for each filter then used the free application eXcalibrator to determine the RGB weighting for color combine. In short, it worked great! eXcalibrator found 13 G2V stars in the image field and from these determined a RGB weighting of 1.000/1.128/1.301 (very close to the results of my manual G2V calibration).

The color balance of the image above has not been manually adjusted from the initial color combine. Complete details regarding this image and more color images of M5 at various resolutions can be found by clicking on the image above or by clicking here.