The Crab Nebula exploded as a supernova burst in the year 1054 AD. Today, we see in this position a remarkable object, several light years in diameter, which is still expanding today. To bring out the dim red hydrogen filaments, Several deep exposures through the red filter were combined to form the Luminance channel. The color information was derived from six binned exposures through a standard RGB interference filter set. This is the first tricolor test with my new focal reducer lens, which decreases the f/ ratio from the normal f/5 to f/2.7. The faster speed works well for the dim tri color frames, and offers a good 15 arcminutes field of view. This also allows the use of the CCD on nights of less than perfect seeing.
Instrument: 12.5" f/5 Newtonian with FR237 Focal Reducer yielding f/2.7 CCD Camera: SBIG237 Exposure: L=Red 3x10m, R=G=B=10mins Binned 2x2 Total Exposure time=60mins Filters: LRGB Location: Payson, Arizona Elevation: 5150 ft. Sky: Seeing 8/10, Transparency 6/10 Temperature: 25 F