Time Series Photometry of Variable Stars in the Globular Cluster NGC 6397

Abstract

Time series BVI photometry is presented for 16 short-period variables located in the central region of the globular cluster NGC 6397. The sample includes 9 newly detected variables. The light curve of cataclysmic variable CV6 shows variability with a period of 0.2356 days. We confirm an earlier reported period of 0.472 days for cataclysmic variable CV1. Phased light curves of both CVs exhibit sine-like light curves, with two minima occurring during each orbital cycle. The secondary component of CV1 has a low average density of 0.83 g/cm^{3} indicating that it cannot be a normal main sequence star. Variables among the cluster blue stragglers include a likely detached eclipsing binary with orbital period of 0.787 days, three new SX Phe stars (one of which has the extremely short period of 0.0215 days), and three low amplitude variables which are possible gamma Doradus variables.

28 pages, 13 figures

References in corpus (3)

• HST color-magnitude diagrams of 74 galactic globular clusters in the HST F439W and F555W bands
• Chandra Study of a Complete Sample of Millisecond Pulsars in 47Tuc and NGC6397
• Photometry and Spectroscopy of the Optical Companion to the Pulsar PSR J1740-5340 in the Globular Cluster NGC 6397

Cited by in corpus (15)

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• MOCCA-SURVEY database I. Accreting white dwarf binary systems in globular clusters -- IV. cataclysmic variables -- properties of bright and faint populations
• Cluster AgeS Experiment. Catalog of Variable Stars in the Globular Cluster Omega Centauri
• HST/ACS Imaging of Omega Centauri: Optical Counterpart for the Quiescent Low-Mass X-Ray Binary
• Cluster AgeS Experiment (CASE): SX Phe stars from the globular cluster Omega Centauri
• Three Additional Quiescent Low-Mass X-ray Binary Candidates in 47 Tucanae
• Photometric study of the variable star population in the globular cluster NGC 6397
• Cluster AgeS Experiment (CASE): Detection of a dwarf nova in the globular cluster M55
• A Blue Straggler Binary System with at least Three Progenitors in the Core of a Globular Cluster?
• Erupting Cataclysmic Variable Stars in the Nearest Globular Cluster, NGC 6397: Intermediate Polars?
• A time-series VI study of the variable stars of the globular cluster NGC 6397
• Low mass variable stars in the globular cluster NGC 6397