Pulsation Modes in Small-Amplitude Red Variable Stars

Abstract

We have investigated the pulsation modes of small-amplitude red variables with well-determined periods and accurate Hipparcos parallaxes by comparing observational and theoretical Q-values. In our sample of 13 stars, one appears to be pulsating in the third overtone, nine in the first or second overtone, and three in the fundamental or first overtone. This result is consistent with the predictions of recent pulsation models by Xiong et al.