Recent studies of the period changes of RR Lyrae variables in the globular cluster M15 have indicated that large ``noisy" period changes are more common among RRab variables than among RRcd variables. Period changes are generally believed to arise through nuclear burning and mixing events associated with the stellar core. The pulsation itself is a phenomenon of the stellar envelope. The apparent coupling of period changes to pulsation mode among the M15 variables is without adequate explanation. In this paper, we explore whether the correlation of period change and pulsation mode extends to clusters other than M15. Possible explanations for the coupling are considered.
American Astronomical Society Meeting Abstracts
- Pub Date:
- December 1995