| Abstract | From analysis of the photometry of Baade and Swope (1961), ten double-mode RR Lyrae (RRd) stars in the Draco dwarf galaxy are identified. The physical characteristics of the stars are derived and compared with those of RRd stars in the Galaxy. Their periods and period ratios are consistent with simultaneous radial pulsation in the fundamental and the first-overtone modes. For each star, the amplitudes of the first-overtone pulsations of the stars are larger than the amplitudes of the fundamental pulsations, as seen in galactic RRd stars. Average beat masses are determined for the sample. Metal abundances for the stars, estimated from their positions in the period-amplitude diagram, are presented. A distance of 84±12 kpc is derived for the stars. Correlations involving the entire system of Draco RR Lyrae stars are investigated. |
