Andromeda Galaxy (M31), H alpha-enhanced

Object(s): M31, M32, M110 Coordinates: RA0h43.5min, DEC41°20.3min Constellation: Andromeda
Telescope: TV-85 at f/5.6 Camera: Parsec 8300M Exposures: 43x1000s H alpha; 30x500sR, 17x500sG, 28x500sB
Location: my back yard, Quadeville Road Date(s): August-September, 2011; August-September, 2012 FOV: 130x100 arcmin
Notable images: Gendler Pugh Neyer

My goal for this project was to produce a very low-noise image, and use an H alpha channel to reveal the emission clouds in the galaxy's spiral arms. To do this, I subtracted the continuum red data from an H alpha image, which with further processing (including cloning away all stars) was dominated by the emission clouds and the galaxy's bright core, which apparently emits quite a bit of H alpha as well. Because this process would inevitably result in a very low dynamic range, and hence be easily spoiled by noise, the H alpha image needed to be very deep: 43x1000s! The result was just good enough to be useful. I think this object would benefit from a luminance layer, which I may capture and add later.

back to galaxies