Combination of 20, 3 minute images, SBIG STL-1001E CCD.
20" f/6.8 cassegrain at prime focus.
PK 158.8 +37.1
Abell 28 is a moderately large, but very faint planetary nebula in Ursa Major. The magnitude is quoted as 13.5 (photographic). However, because of its large size, it is very difficult to observe or image. It is only very weakly recorded in the image above, its location being indicated by the lines. The star the lines are pointing to is the 17.4 magnitude central star.