Challenging Summer Deep-Sky Objects

I suggest not taking the "ratings" too seriously. Don't worry if some of the "hard" objects seem easier than the "easy" objects. It's not clear what size telescope the original authors had in mind; probably something in the 10-14" class, but many of these objects should be easily visible to a practiced observer using a 6" or smaller telescope. All of these objects will be fairly difficult for a beginning observer.

You can get more information about specific NGC/IC objects through the NGC/IC Project Public Database. You can find some images of NGC objects at the SEDS Non-Messier image list. Detailed photographic charts can be downloaded from the Digital Sky Survey.

I intend to add links for each object on this list to images and to the appropriate DSS photo, chart numbers for the Harald-Bobroff atlas (that being what I have; if someone else wants to send me Uranometria pages I'll gladly include them as well) and magnitudes, and other information, as as I get time. If you have a favorite web image of an object listed here, or would like to see information beyond what I've included here, please
tell me about it.

A somewhat similar list, of deep-sky objects which belong neither to the Messier or Caldwell catalogs, is available on the Hawaiian Astronomical Society's Beyond Messier & Caldwell page.