Telescope: Skywatcher 8" f/5 Newtonian
Focus: Prime focus
Camera: SAC7B, uncooled
Exposure: Mosaic of 2 images each 100 &
99 x 25s
Date: 27th July 2003
Processing: The usual YRGB
processing, with the subtraction of a 'banding flat' (see the
Advanced Processing page) to remove
fine banding noise from both images in the mosaic.
A very challenging subject, with low
surface brightness (14.8 mag/sq.arcmin). Extreme curve stretching has led to a noisy image.
The faintest stars visible here that also
appear in the USNO A2.0 catalog are mag 19. However, photometry using
Iris, with reference to the GSC (Guide Star Catalog), indicate stars as
faint as 20.5. This is a million times fainter than the faintest star
visible with the naked eye at my site (mag 5)!