M 3

NGC 5272

01-04-04 about 3 am

M3 (NGC 5272), globular cluster in Canes Venatici.  33,900 light years from earth.  Magnitude 6.4, surface brightness 11.0, 18.6 arcminutes round.  Stacked the results of Astrovideo's log funtion (15 frames @ 10 seconds).   It took 46 minutes to capture.  No dark frame used but needed.  Eyeballed polar alignment.   Optical train was 9.25" sct, f/6.3 r/c,  flip mirror, 15 mm spacer, filter wheel loaded with Orion's Skyglow filter, then SAC 8 camera.  

10 seconds, full gain.