Saturday, April 13, 2013

Whale plays hockey

Finally clouds went away (do not really care where) and I had a chance to make some night exposures. There are so many interesting object and so few clear nights, so the decision is really hard. However this time I pointed my scope to the Canes Venatici (Hunting Dogs) constellation again and made the picture presented below. In the upper left there is NGC4631 The Whale Galaxy with its dwarf companion NGC4627 called sometimes The Whale's Calf. Lower right part of this very tightly framed picture is taken by NGC4656 The Hockey Stick Galaxy

All these three galaxies are (or had been) interacting, so that's why their shapes are so irregular. Pale blue color of the external parts of Whale indicate presence of young massive stars, while yellowish center region is due to the old population of red giant stars. In the star color language blue means hot stars, while red means (relatively) cold star. In this scale our Sun is somewhere in the colder star league with its surface temperature about 5800K and yellow tint.
Picture has been taken with usual setup - 6" diameter f/4.5 newtonian scope with coma corrector and Baader entry level LRGB filters plus Atik 314L+ camera. Exposure time LRGB - 195:30:30:30 minutes, binning 1:2:2:2 with single exposure 3 minutes for L, and 2 minutes for RGB.
Here b/w version - luminance only:

Clear skies!

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