Ccd Observations of the Rr Lyrae Variables in the Globular Cluster Ngc 5897

CCD observations for 10 (6 previously known and 4 newly discovered) of the 11 RR Lyrae variables in NGC 5897 have been analysed. The period-luminosity and period-amplitude plots indicate that the population of RR Lyrae variables in NGC 5897 includes 3 fundamental mode, 4 first-overtone and 4 second-overtone variables with mean periods 0.828, 0.459 and 0.343 respectively. The variables have properties that are similar to some of the Oosterhoff type II variables in ω Centauri. Two of the new variables (V11 and V13) were previously considered to be possible non-variables that lie within or near the instability strip on the horizontal branch; both have V amplitudes less than 0.2 mag. There is a chance that one or two of the variables (V10 and possibly V3) might be anomalous Cepheids and not RR Lyrae stars. Subject headings: globular clusters: individual (NGC 5897) — stars: fundamental parameters — stars: horizontal-branch — stars: variables: RR Lyrae