Instrument

12.5" RCOS @  ~f/9 (2880 mm fl) 1.28 arcsec / pixel.  Shown resampled to 3.1 arcsec / pixel.

Mount

Paramount ME

Camera

SBIG STL-11000 w/ internal filter wheel, AstroDon Filters

Acquisition Data

3/15/2009 to 3/24/2009  Chino Valley, AZ

Exposure

Lum    100 min (10 x 10 min, bin 2x2)

Red       70 min ( 7 x 10 min, bin 2x2)

Green    70 min ( 7 x 10 min, bin 2x2)

Blue      70 min ( 7 x 10 min, bin 2x2)

Software

CCDSoft, CCDStack, Photoshop CS w/ the Fits Liberator plugin, Noel Carboni's actions and Russ Croman's Gradient Exterminator

CCDStack to register, normalize, data reject, combine and luminance sharpen.

PhotoShop for the color combine.

Comment

North is to the bottom.  I think it looks better upside down.

Messier 67 is one of the oldest known open star clusters. M67 contains over 500 stars and lies about 2,800 light-years away in the constellation Cancer. At that estimated distance, the cluster would be about 12 light-years across.

Source: NASA APOD