The long-period field RR Lyrae stars

Fourier decompositions have been performed on several of the VR light curves obtained for 16 faint variable stars with less-than-1-day periods, where the trends of slower rises to maxima and flatter tops than those characteristic of Bailey-type ab RR Lyrae stars are evident. While the Fourier coefficients in such cases are essentially constant for periods shorter than 3/4-day for the Bayley-type ab RR Lyrae stars, the amplitude ratios R(12), R(13), and R(14) decrease, and the phi(21) and phi(23) phase differences increase at longer period. When the Fourier parameters for known anomalous Cepheids are compared with those of RR Lyrae stars, the scatter is found to preclude an unambiguous segregation of the anomalous Cepheids from the RR Lyrae stars. 16 refs.