M-46 (NGC-2437) is a rich open star cluster located in the constellation of Puppis, about 14 degrees east of the brilliant star Sirius (Alpha Canis Majoris). It was discovered by Charles Messier in 1771, and entered in his catalog as number 46. It contains over 200 stars ranging from 10th down to 14th magnitude. This cluster lies at a distance of 5400 light years from Earth and is 75 light years in diameter. A curious feature of this cluster is the presence of the small planetary nebula NGC-2438, located approximately 7 minutes of arc north of the center of the cluster. It shows up well in this image, just to the upper right of the center of the cluster. It is not an actual member of the M-46 cluster, being about 3000 light years from Earth. This means that it is just an "optical" or "line of sight" member.
This image, captured on March 14, 2013, is a 30 minute integration of 4 minute exposures through the Celestron C-11 at f/2, using the HyperStar III imaging system and the Starlight Express SXVR-H694C color CCD camera. Guided, captured and combined using Maxim DL5 Pro. Post processed using PhotoShop CS2
Gradient XTerminator, StarShrink, Carboni's Astro Tools and NoiseWare.