Collecting Photons
M99 - M98 - NGC 4302 et al. Coma Berenices
North is above. 1600x1075 Full resolution (3816x2565)
Objects: A school of galaxies surrounding M99. See the overlay.
Constellation: Coma Berenices
Coordinates of field center: 12h 18m +14° 33'
Notes: Galaxies to go in any conceivable format and size. The overlay labels only the most obvious specimen but, as the full resolution image demonstrates, the field is literally filled. In the following panel I have cropped some of the most interesting morphologies.
Telescope and camera: ASA 10', f 3.6; SBIG STL 11000.
Exposure: Luminance 42x8'; R, B 16x10''; G 16x8". About 13 hrs total.
Date: 5 nights on 11, 17, 18, 19 and 21 April 2010.
Software used: Acquisition, CCDsoft, FocusMax, Autoslew-OK3, CCDcommander. Calibration; registration and stacking: CCDstack. Processing: PixInsight, Photoshop CS.
Processing had two goals from the very start: a) maximum colur discrimination within the tiny galaxy profiles and b) optimal detail extraction. The long integration was necessary for both goals. The luminance layer was obtained blending together three different levels of deconvolution (20, 100 and 200 iterations) according to the brightness of the extended source. At the same time stars have been protected to prevent ringing artefacts. Colour enhancement was performed in the cLab space Finally, multiscale unsharp masking was used to enhance the details present in the countless galaxies.
This image has a special meaning for my observatory, since it is the first image acquired in full automation thanks to CCDcommander.
M98 - NGC 4192A - NGC 4186
A nice composition with the blue (A3V) bright star 6 Coma Berenice on the left and two tiny spirals just south of M98.
M99
The tidal tails of IC 3091
IC3091 is the tiny galaxy (1.3'x0.6') in the lower left corner. It is extremely distorted and this can be well appreciated in this image from the Sloane Digital Survey . The pretty side-on galaxy on the right is IC3061
Copyright © 2010 by Gimmi Ratto. (May13, 2010)
