Comment Re:Astronomy! (Score 4, Informative) 398
In all fairness, if you want to make a contribution that is worth co-authorship of a paper, you might need at least a good amateur telescope (maybe on the order of 10 inch aperture) and a CCD camera.
With such equipment, and clear skies, you can do photometric monitoring of stars (e.g. for outbursts, or planet transits). Asronomers always have the problem that big observatories focus on big telescopes, and it's difficult to do things that require small telescopes, but long-term monitoring.
One example would be monitoring of the transits of extrasolar planets, to detect timing anomalies (which could be caused by undetected additional planets). Or monitoring stars with planets detected by radial velocity variations, to discover eventual transits. Or monitoring of ongoing gravitational lens events... there are quite a few oportunities for amateurs.