Here's a little thing I like to call the Great Globular Cluster in Hercules. You may recall this image from my two previous attempts. I saw the APOD a couple of weeks ago and was motivated to try and improve the ones I had already posted. This uses last year's data along with more data captured this year. This is just an RGB image, I decided not to use Luminance. I also rejected a whole mess of data (for instance, the data that was causing the arc in my previous efforts). Total integration time is now about 6 and a half hours.
Little in the way of processing: my usual data reduction (with flat fields) and SD Mask stacking in MaximDL, a masked stretch, non-linear stretching, noise reduction on the background, and a modest saturation boost in Pixinsight. One interesting thing I did do is use a tool named eXcalibrator in conjunction with Aladin which matches the image to SDSS or NOMAD data and determines the proper weights for the color channels. So this is probably much more faithful to "true color" as a consequence. I also oriented the picture properly so North is up.
Another interesting note. If you look closely at the little galaxy in the upper left you can see the color of the H2 regions therein (pretty cool, hadn't seen that before).
Here it is:
- M13
Enjoy,
-esy
