Abstract
The American Association of Variable Stars Observers coordinates, collects, evaluates, and archives variable star observations made largely by amateur astronomers around the world and publishes and disseminates
these observations to researchers and educators worldwide. Its database of nearly 10 million observations is the largest and longest running in the world. The AAVSO website (http://www.aavso.org) is quite extensive.
The AAVSO has a long history of collaborations between its amateur astronomer observers and professional astronomers. Many of the 250- 300 requests received yearly from astronomers for AAVSO data and services result in collaborative projects - particularly to help schedule
observing runs with ground-based telescopes or with instruments aboard multiwavelength satellites, to provide simultaneous optical coverage of observing targets and to correlate multiwavelength data.
The AAVSO, its observing programs and database are described and various successful AAVSO collaborations between professional astronomers and amateur astronomer observers involving space satellites are summarized.
