I have practiced astronomy as a hobby for a while now. I have an entry-level telescope (6-inch Newtonian). In addition to observing the night sky, I have been studying physics related to optics, astronomical distance & temperature measurement, gravity, etc.
My plan is to next get a CCD camera, and do some astrophotography. It should keep me busy the next winter. However, I feel I should try to find some kind of project where I could gradually make progress. Otherwise, after learning all the basics, and seeing everything that can be seen with the smallish telescope I have, I might gradually start to lose interest.
What would you recommend as the "next stage"?