Collecting  Photons

North is up. Half resolution 2990x1930

Objects:             The Cone Nebula on the left is, of course, the most famous feature of the area. However around here there are so many wonders to explore! Right at the center meet the golden cluster Trumpler 5, a very unusual ancient open cluster densely populated of red giants. The younger open cluster NGC 2259 is near theupper edge of the frame. At the right side there is a fantastic structure of dust and reflection nebulae, with the large and bluish IC447 surrounded at he north by a cohort of other nebuae with a very interesting structure. Looking carefully, one can detect the red signature of HH objects. The link directs to a very large image that is only half as large as the original. Open the link and surf the starfield and have fun.

Constellation:     Monoceros

Coordinates of field center (J2000): 6h 37m; +10° 01'

Notes: I have dreamt of making a mosaic of this area since I have got the STL11000 for the ASA astrograph. My friend Davide, co-owner of the remote observatory, started shooting the Cone and that was all that was needed to start the projects. We got lucky with the weather and so it took only 10 days to accumulate the necessary data. I have used only the data from the ASA since I wanted a field as large as possible and the TEC, given its slightly longer focal was cropping the image too much. So I ended up with a shorter integration than I was hoping for but the data were good and handled the stretching quite well.

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

Exposure: HαLRGB composition. Each panel includes Hα 6x30'; L 13x10'; R,B 7x10'; G 7x8'. About 25 hrs total.

Date: ten nights on November and December 2011.

Software used: acquisition, CCDsoft, FocusMax, The Sky VI. Calibration; registration and stacking: CCDstack, Registar; processing: PixInsight 1.7, Photoshop CS3. 

Processing notes: processing was not easy at all. First whole the seamless creation of the mosaic required great attention in the data calibration and in offset correction, in order to arrive to the mosaic composition with data as homogeneous as possible. The mosaic was composed using the amazing tools provided by Pix Insight, may they live long and prosper, but at the end the colour data needed quite a bit of careful doctoring to fix a few nasty illumination artefacts. Finally, the real problem was the enormous dynamic range of the image. The cone and the open cluster just north of it are enormously bright and dominates the entire area. It required many different tools to balance in a coherent picture all the elements of the composition.

Copyright © 2011 by Gimmi Ratto. (December 14, 2011)