A study of double- and multi-mode RR Lyrae variables

TL;DR

This study analyzes RR Lyrae stars using Catalina Surveys data, identifying double-mode pulsations, studying their period distributions, and discovering non-radial pulsations, revealing similarities between field and cluster RR Lyrae stars.

Contribution

It provides new insights into double-mode RR Lyrae variables, including their period distribution and the discovery of non-radial pulsations, enhancing understanding of their evolution.

Findings

Double-peaked period distribution in Galactic RR(B) stars.

Similarity in age and evolution between field and cluster RR Lyrae stars.

Discovery of five RRC stars with non-radial pulsations.

Abstract

We present the results of our new study of known RR Lyrae variable stars. All observations available for these stars in the Catalina Surveys were analyzed, and double-mode variations were identified. We studied the Petersen diagram and period distribution for the double-mode RR Lyrae variables in the Galactic field, pulsating in the first-overtone and fundamental modes. The double-peaked character of the period distribution was detected for Galactic RR(B) stars, corresponding to Oosterhoff's classes of globular clusters, which indicates that the age and evolution stage of RR(B) stars in the field and RR Lyrae variables in globular clusters are probably the same. Besides, we discovered five RRC stars with two simultaneously excited non-radial pulsations (equidistant triplets).