Whale and Hockey Stick Galaxies


Ron Brecher

Guelph, Ontario, Canada

SBIG STL-11000M camera, Baader RGB filters, 10″ f/6.8 ASA astrograph, Paramount MX. Guided with STL-11000’s internal guider. Focused with FocusMax. Acquisition, guiding and calibration with MaximDL. Image registration and all processing in PixInsight. Shot from my SkyShed in Guelph, Ontario. Thin crescent moon. Average transparency and seeing throughout.

10x15m R, 5x15m G, and 10x15m B, all unbinned frames (total=6hr15m).

Complete processing details at http://astrodoc.ca/ngc-4631-and-4656/

NGC4631 (top left) and NGC 4656 (bottom right) are known as the Whale Galaxy and Hockey Stick Galaxy, respectively. The Whale is distorted due to its interaction with NGC4627 just to its left. The Whale shows a yellow core, blue star clusters and pink nebula. It is about 25 million light years away. The Hockey Stick, lying about 30 million light years distant, is distorted by a small galaxy just of the tip of the “blade.†In this region of sky there are galaxies everywhere, and you can find many more in this picture. Look for streaks (e.g. above centre left, and centre right) or fuzzy patches that don’t look like the other stars. I acquired the data in 2014, and this version replaces the one previously posted here, for those who are interested in seeing how my processing has changed over time. I think this shot would benefit from a lot more imaging time, and I plan to go back to it this spring.