Creech-Eakman, Michelle J.

Contact Email: mce@huey.jpl.nasa.gov
Institute: California Institute of Technology, Jet
Propulsion Lab
First Coauthor: Robert R. Thompson
Institute: JPL and Univ. of Wyoming
Research URL:http://huey.jpl.nasa.gov/~mce
Subject Area: Stellar Atmospheres, Circumstellar Material
Waveband: Infrared
Technique: Interferometry
Presentation: Poster Display
Title: Pulsation Modes of Mira Variables Investigated using NIR Interferometry
Abstract: We have undertaken a program (1999 to present) with the Palomar Testbed Interferometer to measure the angular size variations, with respect to pulsational phase, of a group of about 50 mira variables, approximately 30 of which are M-types. While we have unambiguously detected the pulsation of the miras with phase (Creech-Eakman et al. 1999 and Thompson et al. in prep.), our main goal with this study is to determine through direct detection methods whether mira variables pulsate in the fundamental or first-overtone mode. To this end, we use our angular diameter measurements with the best estimates of stellar distances to determine if a particular pulsation mode can be identified for the oxygen-rich stars in our sample. We also correlate our results with respect to spectral type, temperature estimates and period to determine what trends are evident for the sample. The unambiguous determination of the pulsational behavior of Mira variables may eventually render them suitable as standard candles for distance determination.