NGC 6826 also known as Caldwell 15, is a planetary nebula located in the constellation Cygnus 'The Swan." It is commonly refered to as the "blinking planetary," although many other nebulae also exhibit such "blinking."
ABOUT THE IMAGE
DATE/TIME: Taken on the evening of September 5th, 2013.
CAMERA: Canon XSI, 450Da
TELESCOPE: Celestron C9.25" SCT @ F/20
ISO SETTING: 800
EXPOSURE LENGTH: 200sec.
TOTAL EXPOSURE LENGTH: 56min, 40sec.
SUBTRACTIONS: 16 dark frames, 10 bias frames.
STACKING/PRE-PROCESSING: Deep Sky Stacker
PROCESSING: Photoshop CS3