POWRE: Infrared Variability of Mira Stars

East Tennessee State University, Johnson City TN

Investigators

Abstract

AST-0073853 Smith The Cosmic Background Explorer (COBE) satellite database will be used to develop Near-Infrared (NIR), Mid-Infrared (MIR), and Far-Infrared (FIR) light curves of carbon and oxygen-rich Mira stars. These new light curves will be compared to visual light curves. This will provide, for the first time, the link between photospheric variations and circumstellar shell variations. At present, MIR or FIR variability has been observed in a handful of stars. Generally, only a small fraction of the visual light curve has been sampled. The COBE DIRBE instrument data will be used to provide information to increase the sample size dramatically, generally with better sampling of the light curve. This data will be used to search for phase lags between the optical and infrared light curves and to search for differences in the amplitude of the variations at different wavelengths. The result of the research will be an atlas of infrared light curves of Mira variable stars. The atlas will contain the photometric data as well as estimates of the circumstellar parameters. These results will provide strong constraints on current models of dust formation, destruction, and heating in circumstellar envelopes. This project is funded by the Division of Astronomical Sciences and the Office of Multidisciplinary Activities in the Mathematical and Physical Sciences Directorate. ***