NGC7000, North America Nebula (H-alpha)
Click image for full size version
Sept. 6, 2010
The North America Nebula is a huge complex of emission nebula in northern Cygnus. This image was shot through a H-alpha filter that allows through only a narrow band of red light. This shot was used to boost the red and detail in the colour image that I prepared separately. You will note that the stars are smaller, fewer and less dominant in this image compared to the colour shot. Also lots of detail and subtle variations in grey are visible throughout the whole image.
Acquired using Nebulosity 2 software, QHY8 camera (Gain=0; Offset=125) with UV/IR and H-alpha filters and an 80 mm f/6 refractor on an MI-250 mount. A field flattener reduced focal length to 384 mm. The mount was autoguided using PHD software, and the KWiqGuide system from KW Telescope.
30x10m through H-alpha filter (total exposure =5 hr)
Light frames were calibrated with 9 darks (bad pixel mapping only), 25 flats and 50 bias frames. The calibration was done in Images Plus 3.0. Alignment, stacking and processing were done using PixInsight. Final image was saved as a jpg at full scale, about 3 arcsec/pixel, with minimal cropping. Shot from my SkyShed just north of Guelph, ON.