|Globular Cluster M 22 - Photo by Mark Lang|
Deep-Sky Planner provides a number of resources to help. You can search various catalogs in the database, and you can download several plans from the Plan Library that contain specialized lists of globular cluster. Current these include:
- Astro League Globular Clusters
- RASC Globular Clusters
- Palomar Globular Clusters
- Terzan Globular Clusters.
The latter two lists are designed for imagers and observers with large telescopes. The data for these lists are taken from the SIMBAD astronomical database and are supplemented with magnitude and color information gathered by W.E. Harris of McMasters University in Canada.
These are small, faint clusters so you will likely want to download and view DSS images of these objects. Although these clusters have been studied for many years, magnitude and color information is missing for many of the objects.
*AL Globular program material: https://www.astroleague.org/al/obsclubs/globular/globular1.html
*RASC Globular program material: Edgar, James S. Observer's Handbook 2017, Toronto: Royal Astronomical Society of Canada, 2016, p312. Print.