AAVSO: American Association of Variable Star Observers

Variable Star Spectroscopy: Tools, Techniques, and Recent Results (Abstract)

Volume 36 number 2 (2008)

Matthew M. Beaky

Abstract

(Abstract only) For well over a century, variable star observers have catalogued changes in the brightness of thousands of variable stars. In contrast, there have been very few efforts to monitor changes in variable star spectra over time. This is unfortunate, because spectroscopic observations of variable stars can provide important additional information about the complex physical processes occurring within and around the star itself. For example, the presence of hydrogen emission lines in the spectra of Mira variables indicates the presence of shock waves in the upper atmospheres of these stars. In this presentation, I will describe some of the resources available for making spectroscopic observations of variable stars with small telescopes, including spectrographs for data acquisition and software for data reduction and analysis. The process of observing a stellar spectrum will also be described, from image acquisition, through wavelength and flux calibration, to the extraction of stellar parameters such as spectral class and atmospheric composition. Finally, I will present results from ongoing research at the Truman State University Observatory to monitor spectral changes in Mira and semiregular variable stars.