IC2177, The Seagull Nebula. This large patch of nebulosity lies on the border of Monoceros and Canis Major at a distance of about 3,600 light years. It was discovered by the welsh astronomer Isaac Roberts. The equipment I was using was my 4 inch f/6.3 refractor, a Vixen Atlux mount, PHD auto guiding, an Atik 383L mono CCD camera with a set of astronomik narrowband filters, HA , S11 and O111. I also used a blue filter to try to reveal the colour of the stars. The sky conditions were good with stars visable down to magnitude 5.5. This four section mosaic was taken on three separate evenings. The camera was set on X2 bin mode increasing the camera's sensitivity by four times. I captured two minute subframes with matching dark frames and combined them with flat field frames to reduce the effect of noise and vignetting in the final image. The total exposure time was 30 minutes for each filter.
Hubble palette
Bicolour
RGB
