M1 - Crab Nebula (LRGB)

M1 - Crab Nebula (LRGB): The Crab Nebula in Taurus is the remnant of a supernova that was observed exploding in 1054.

Messier: 1
NGC: 1952
Right Ascension: 5hr 34.5m
Declination: 22d 01m
Apparent Magnitude: 8.4

Date: October 2009
Equipment:
Telescope: Meade 16" Schmidt Cassegrain with f6.3 reducer
Camera: SBIG ST-10XE
Guiding: Meade 5" refractor/DSI Pro/PHD

Exposure:
Luminance 21x3min
Red 4x5m
Green 4x5m
Processing Notes: The camera was at -25C. The data was reduced and aligned in CCDStack, and combined in Sigma Beta, and saved as a 32bit FIT. The RGB data were combined in AstroArt at 1:1:1.5 and saved as a TIFF(view). The RGB channels got a small gaussian blur on the dim areas in Photoshop. The luminance file was imported to Photoshop using a Fits Liberator sqrt(x) stretch function. Noise was reduced using the Photoshop "reduce noise" function, and the dim areas also got a minor gaussian blur. Brighter areas were sharpened using an unsharp mask. A 25% minimum filter was applied to only the stars. L was combined with RGB using three layers: Luminance on the bottom; RGB as a multiply(40%); and RGB as a color layer on top. Final stretch and tweak (including fixing the one "dripping" star) in Photoshop.
Scale: 1.01

Links to images of this object on other sites:
http://www.narrowbandimaging.com/m1_mk1sn2_s2hao3_page.htm
http://hubblesite.org/newscenter/archive/releases/2005/37/

Additional Comments: The seeing was above average for Durango. (Maybe 7/10?) FWHM on all subs was less than 3".

Several other images of the Crab Nebula can be found on this web site by searching for M1.

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