Periodicities in delta Scuti frequency spectra along the HR diagram

A. García Hernández, J. Pascual-Granado, A. Grigahcène, A. Moya Bedón, S. Martín-Ruiz, J. Gutiérrez-Soto, J.-C. Suárez, R. Garrido

Abstract.
Delta Scuti pulsating stars are challenging but interesting targets. They constitute good laboratories for stellar physics theories (such as convection) mainly for the complexity of their structure as reflected in their complex frequency spectra. Any classical asteroseismic study of these stars by individual frequency fitting does not give accurate results and the analysis is not too much useful. Hence, more observables are needed to help in their study.
Some authors have claimed to find periodicities in the frequency spectra of a couple of stars observed from the ground (FG-Vir, Breger et al. 1999; CD-24 7599, Handler et al. 1997). Using CoRoT observations, we have definitely confirmed the presence of such regularities in the frequency spectra of HD 174936 (García Hernández et al 2009) and HD 174966 (presented at the 2nd CoRoT symposium). However, the first question to be addressed at this level is: are these stars peculiar cases? The large sample of delta Scuti stars observed by Kepler offers us the possibility of carrying out an statistical analysis and of studying the behaviour of such structure along the HR diagram. In this talk, we will present the very preliminary results of our work.

20th Stellar Pulsation Conference Series
Granada, Spain
setembro 2011

Tipo: Comunicação oral