Roll over for the Hα data 1600x1067
Objects: The supernova remnant Ctb-1 (Abel 85).
Coordinates of field center: 24h 00m +62° 31'
This is an extremely faint supernova remnant with a marvelous symmetric shape.
It proved to be very hard to image given the low contrast.
Telescope and camera: ASA 10', f 3.6; SBIG STL 11000.
Exposure: Hα 42x16'; R, B 9x10'; G 9x8'. About 15.4 hrs total.
Date: 6 nights on 21, 22 and 26-29 October 2010.
Software used: acquisition, CCDsoft, FocusMax, CCDcommander, The Sky VI. Calibration; registration and stacking: CCDstack, Registar; processing: PixInsight, Photoshop CS.
Processing notes: The RGB data is not very deep, running short of 5 hours of overal integration, but there was almost no trace of the nebula, if not for some hint of the brightest rim of the bubble. The narrow band data had to be so much deeper that it was pretty difficult to prevent it to contaminate the stars. I had to use very energetic masks for the correct blending of the stars with the nebula.
Copyright © 2010 by Gimmi Ratto. (November 10, 2010)