Sky this Week

I recently received the “Galaxy Groups and Clusters” book from the Astroleague and decided to try imaging some of the listed objects. Below is an image of NGC 5171 in constellation Virgo. There are at least 9, probably more galaxies shown in the image which I’ve identified 7.

Location Louisville, CO, time 11:45 to 0:015 MDT. Weather clear, temperature 57°F, humidty 60%, no wind, clear sky, transparency very good, turbulence good (6/10). Equipment used was a Celestron Nexstar11, Meade F3.3 focal reducer, and Astrovid Stellacam II video camera. Integration at 256, gamma at medium and gain at 9/14. Fifteen minutes of video was dark subtracted, flat field and bias corrected. Aligned and stacked with Registax3, brightness enhanced with ImagePlus, cropped and labeled with Photoshop Elements2.

Contained in about 6 arc-minute area are seven galaxies to challenge those with large aperature scopes and dark skies (or Stellacams from light polluted backyards). I didn’t have the gamma set correctly set on the Stellacam when I took these. I’m learning that the gamma setting needs to be on medium for faint objects — if it is off there is not much to stack. There should be more detail, I’m going to visit this object again soon. Image taken last evening, April 20 just after midnignt with Nexstar11 telescope, Meade F3.3 focal reducer, and Stellacam2 video camera, gain 9/14, gamma off (unfortuantely), and integrate at 256.