Wednesday, August 9, 2017

A Celestial Crescent--Imaged 8-8-2017

I have never been able to image the Crescent Nebula; even under dark skies, the nebula did not show in any of my images. Last night, I hooked my Mallincam DS16C to my f/4 Newt astrograph and turned on a new feature--digital binning. Of course, there's nothing new about binning, but, up to now, that capability did not extend to CMOS-based imagers like the DS16C.

This addition adds huge sensitivity to an imager like the DS16C. At 2x2 binning, I was able to image the crescent at gain 15 with a 15-second integration, with a full moon in the sky close by and with no filtration!  Here is a processed stack of  50 images:


A single, raw integration shows how sensitive the binned imager is:


The Crescent is an emission nebula--it is the result of a shock wave from a Wolf-Rayet star (a rare, massive, and highly luminous star) slamming into a slower moving wind produced by the star when it became a red giant, more than a quarter of a million years ago. The star is WR136 or HD192163. In this astrometry.net analysis of the image, the star is shown towards the bottom of the crescent (the labels of the star and the NGC designation unfortunately over write each other).