2018-03-20
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Night of UTC 2018-03-20
Mt. Kent Observatory
CDK700
Apogee U16 camera at -10C

Credit: Rhodes Hart and John Kielkopf


Clear sky (some lines of cloud to SW)
Crescent moon (near new) (set early in evening)
Some wind

NGC 2244  (Rosette Nebula Cluster)   06 31 55.0 +04 56 30 (Simbad)
griz 16s and 128sec  then series of r' 128s   Focussed.
       

Exposures of 128 second in each of  g', r', i', and z'
Processed for dark subtraction with WCS added by astrometry.net software
Images combined in  ds9, displayed on a square root scale to show the
  faintest stars and make the background slightly grey in all colors
  
RGB mapping of Sloan filters

  i --> red
  r --> green
  g --> blue       

Hydrogen (H-alpha and H-beta) appears blue green.  Red stars are exceptionally
cool IR-bright.  

The image shows most of the faint stars that appear in the DSS on Simbad.