Instrument

12.5" RCOS @  ~f/9 (2880 mm fl). Imaged at 1.28 ArcSec/pixel,  shown resampled to 1.88.

Mount

Paramount ME

Camera

SBIG STL-11000 w/ FW8 filter wheel, AstroDon Filters

Acquisition Data

4/6/2014 to 4/25/2014  Chino Valley, AZ. with CCDSoft and CCD Commander

Exposure

RGB    360 min.  (12 x 10 min. bin 2x2) each

Software

• CCDSoft, CCDStack, PixInsight and Photoshop CS6.

• eXcalibrator v4.25 for (g:r) color balancing, using 64 stars from the SDSS-DR9 database.

• CCDBand-Aid to repair Kodak KAI-11000M vertical bars.

• CCDStack to calibrate, register, data reject, combine the sub exposures and create the RGB image.

• PixInsight for gradient removal and initial non-linear stretching.

• PhotoShop for the final touch-up.

Comment

North is to the top.

Also cataloged as NGC 5024, the cluster was discovered by Johann Elert Bode in 1775. M53 is in the constellation Coma Berenices, at a distance of about 58,000 light years from the earth. At about 60,000 light years, the cluster is the most distant from the Galactic center. M53 contains over 250,000 stars.