M100

M100: M100 is a nice face-on spiral galaxy in the constellation Coma Berenices. It is one of the brighter galaxies in the Virgo cluster. The elliptical galaxy to the right in the image is NGC 4328, and the one near the bottom is NGC 4322. Numerous background galaxies are also in the field of view.

Messier: 100
NGC: 4321
Right Ascension: 12h 22m 55s
Declination: 15° 49' 19"
Apparent Magnitude: 10.1

Date: May 2010
Equipment:
Telescope: Meade 16" Schmidt Cassegrain with f6.3 reducer
Camera: SBIG ST-10XE
Guiding: Meade 5" refractor/DSI Pro/PHD

Exposure:
RGB: 9x5minutes each
L: 15x5minutes
The camera was at -30°C.

Processing Notes: Data acquisition with CCDSoft. Reduced and aligned in CCDStack. Deconvolution of the L in CCDStack. Subs combined in Sigma Beta. RGB combined in AstroArt at 1:1:1.5 ratio. Arcsine stretch import of deconvoluted L into Photoshop. Adjusted curves and levels. Slight blur on the dim areas and sharpening on non-star bright areas. 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 in Photoshop.
Scale: 1.0"/pixel

Links to images of this object on other sites:
http://www.noao.edu/outreach/aop/observers/m100.html
http://antwrp.gsfc.nasa.gov/apod/ap010203.html

Additional Comments: The halo around the galaxy is real. The arc to the upper left of the galaxy is an artifact from a reflection somewhere in the optical path. This is a first try at deconvolution of the L channel in CCDStack. Definitely some star artifacts from that.

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