Exploring the Digitized Sky Survey

NGC 7023 (Caldwell 4) - a reflection nebula in Cepheus

The effect of stretching the image, using the Digital Development
option in MaxIm DL, can be quite dramatic. This is one of the reason
why I am concerned when I read about the discovery of new astronomical
objects based on short exposures using small telescopes.

I think it is quite clear from the image that the cloud of gas and
dust known as Caldwell 4 is significantly larger than just the portion
reflecting the star light (and hence appearing blue) - look at the
dark zones around the perimeter where there are few, if any, stars.

http://martin-nicholson.info/ngc7023/ngc7023.htm

Martin Nicholson, Daventry, England.
http://www.martin-nicholson.info/1/1a.htm

Visit the Astronomical Hall of Shame at http://www.geocities.com/queen5658/