Collecting  Photons

Roll over to see the Hα image 1600x1082 Hα 1600x1082

Objects:             IC443, VdB 75 (IC 444), Sh2-249, LbN 840, 841, 844, 845.

Constellation:     Gemini

Coordinates of field center (J2000): 6h 18m 56; +22° 48'

Notes: This field has everything: a supernova remnant, subtle HII areas, three reflection nebulae of three different colours (find the third one!) and some dark clouds. Hints of dust can be found around the edges of the nebula. It also sports two very bright orange stars (m and h Geminorum) that required some heavy duty thinking!
 

Telescope and camera: ASA 10', f 3.6; SBIG STL 11000.

Exposure: Hα 24x16'; Luminance 14x8'; R, B 10x10'; G 10x8'. About 13 hrs total.

Date: A very poor winter meant that I could start imaging this object so late that it was already past the meridian for most of the night. So it took 5 nights on February-April 2011 to collect insufficient signal. It will have to suffice, for the time being.

Software used: acquisition, CCDsoft, FocusMax, CCDcommander, The Sky VI. Calibration; registration and stacking: CCDstack, Registar; processing: PixInsight 1.6, Photoshop CS. 

Processing notes: a very bright object but with some interesting problems: two monster stars with huge halos and too many bright stars that required at least 5 steps of processing to be properly attenuated. Most of the processing, except the layer composition, has been performed in the full version of Pix Insinght. Amazing, amazing program!

Copyright © 2011 by Gimmi Ratto. (April 3, 2011)