M44, The Beehive Cluster, Praesepe
Click image for full size version
February 12, 2012
A few nights ago, I got a 60-minute window of clear sky, albeit under a nearly full moon. I took advantage of this brief time to capture the attached picture. I decided on something bright and non-nebulous, since the moon was washing out the background sky badly. The main subject of the image is M44 (Messier 44), also known as the Beehive and Praesepe (Latin for manger). It’s a large, loose open cluster of stars in the direction of Cancer, the Crab. It shows many blue-white stars, and a few reddish stars. The colours show well in the attached shot. In addition to this relatively close cluster located in our galaxy, the Milky Way, the image shows many, many background galaxies much further away.
17x1m L, 2x2m R, 3x2m G and 4x2m B unbinned frames (total=35m). SBIG STL-11000M camera, Baader LRGB filters, 10″ f/3.6 ASA astrograph, MI-250 mount. Guided with internal guider in main camera. Acquistion, guiding, calibration, registration, integration and initial colour balance all done using Maxim-DL. Shot from my SkyShed in Guelph, Ontario. Nearly full moon, average transparency and poor seeing.
The LRGB image was created in Maxim-DL using the “Stack” command. PixInsight was then used as follows: Dynamic Background Extraction, Colour Balance, Stretch, ACNDR noise reduction (small scale), reset black point, ACNDR noise reduction (larger scale), reset black point, , curves, saturation, convolution on cores of brightest stars.