I use variable stars to study the nature and evolution of stars. My current interest centers on
pulsating red giants and supergiants, which represent the semi-final stages of stars’ lives, and are poorly-understood, compared with other variable star types. I use archival data, especially from the
American Association of Variable Star Observers (AAVSO), which stretches back for a century or more, edit the Journal of the AAVSO, and otherwise facilitate the contributions of skilled amateurs to
variable star research. I am also engaged in a wide variety of astronomy education and outreach projects.