The AAVSO has been around for over 100 years. Despite its name of American Association of Variable Star Observers, the AAVSO is an international nonprofit organization where both amateurs and professionals meet and work together to further our astronomical understanding through variable stars. This lesson will highlight some of the collaborative aspects and educational aspects available to an association with the AAVSO.
The group of Extrinsic variable stars covers the variable star classes: Eclipsing, Rotation, and Microlensing. This group of stars is classified based on external factors causing the changes to the star, and thus the variability to their flux.