Spectroscopy of an apparently nonvariable star within the RR Lyrae gap of the globular custer NGC 5897.
Two spectra have been obtained of SK 120, a possible nonvariable horizontal-branch star within the RR Lyrae gap of the globular cluster NGC 5897. The metal abundance of SK 120 was found to be [Fe/H] = -1.6±0.3 by the ∆S method, consistent with membership in NGC 5897. The radial velocity of SK 120 was also found consistent with membership. The effective temperature of SK 120 was estimated to be 7000±200K from previous (B-V) photometry and from the spectra. It is argued that SK 120 is unlikely to be a field star. On the horizontal branches of M3 and M15, an effective temperature of 7000K would place SK 120 within the RR Lyrae gap. Implications of the nonvariability of SK 120 are discussed and further observations are suggested.