Galaxy M109 in Ursa Major

The aurora in this image is the result of a reflection in the optical system caused by a star just outside the field of view. After taking this image I have been flocking the inside of the AO-7 adapter ring, which was a major contributor to this problem.

For this image, I have used a longer exposure time for the blue filter than for the other two, to compensate for the lower sensitivity of the main CCD for this color.

This is the first image I used my newly built light box for to do flat field correction.

2004-01-21: Luminance 50 minute exposure (5x600s). R and G binned 2x2 10 minutes (1x600s), B binned 2x2 16 minutes (1x960s). Camera cooled to -20°C.