NGC 281 is a H II emission nebula located in the constellation Cassiopeia.  The nebula was discovered in August 1883 by B. B. Barnard, who described it as "a large faint nebula, very diffuse."  NGC 281 is also known as the Pacman Nebula for its resemblance to the video game character.

http://en.wikipedia.org/wiki/NGC_281

 

ABOUT THE IMAGE

DATE/TIME:  The evening and early morning of August 23rd and 24th, 2011.

CAMERA:  Canon XSI, 450D modified

TELESCOPE:  Orion 100ED @ F/7.65

MOUNT:  Celestron CG-5GT.

ISO SETTING:  800

EXPOSURES:  31

EXPOSURE LENGTH:  600sec.

TOTAL EXPOSURE LENGTH:  5hrs 10min.

SUBTRACTIONS: 10 dark frames, 10 bias frames, 20 flat frames.

CAPTURE: MaximDL

STACKING/PRE-PROCESSING: Deep Sky Stacker

PROCESSING: Photoshop CS3