What can amateur astronomers contribute to follow-up observations now that the Hipparcos and Tycho Catalogues are available?
A. A huge amount! A large number of new variables have been discovered, and many of these reveal interesting features in their light curves that require follow-up observations. For example, there are many new eclipsing binaries for which only a single minimum has been observed by Hipparcos. These need additional ground-based observations to pin down their period. We refer interested observers to the web pages of the AAVSO for more details.
