Sh2-46 is


Ron Brecher

Ontario, Canada

SBIG STL-11000M camera, Baader Ha, R, G and B filters, 10″ f/6.8 ASA astrograph, Paramount MX. Guided with QHY5 guider and 80 mm f/6 Stellar-Vue refractor. Acquisition and guiding with TheSkyX. Focusing with FocusMax. Automation with CCDCommander. All preprocessing and processing in PixInsight. Shot from my SkyShed in Guelph, Ontario. Nearly full Moon for Ha and no moon for RGB. Good to average transparency and seeing throughout acquisition.

28x20m Ha, 12x15m R, 12x15mG and 12x15mB unbinned frames (total=18hr20m).

Complete processing details at

The nebulae in the Sharpless catalogue range from tiny to huge in apparent size, and from extremely dim to bright. Sh2-46 is is sort of in the middle of the pack; neither very bright nor very dim; and intermediate in size. It lies in Serpens, and is around 2,000 light years away from us. It’s width is about half the Moon’s width. Sh2-46 doesn’t seem to be a very popular imaging target, and I wasn’t able to find many other images or additional information about it. This image blends the typical red, green and blue colour channels with data collected through the deep red Hydrogen-alpha filter.