Serendipitous Discovery of a Cataclysmic Variable in the Globular Cluster NGC 6624

Abstract

Despite indications that classical cataclysmic variable (CV) stars are rare in globular clusters in general, and in the cluster NGC 6624 in particular, we have serendipitously discovered such a star ~6'' from the cluster center. A Hubble Space Telescope spectrum of the m~22 object shows strong, broad emission lines typical of numerous field CVs, and the inferred optical and UV luminosity are also similar. Our accidental observation also provides the first high-quality ultraviolet spectrum of a globular cluster CV. That we have detected such an object in an observation that includes just a few percent of the central area of the cluster may indicate that cluster CVs are more common than previously thought, at least near the core.

11 pages including 4 figures and 1 table. Accepted for publication in The Astronomical Journal, December 1999

References in corpus (1)

• Astrometry with Hubble Space Telescope Fine Guidance Sensor 3: The Parallax of the Cataclysmic Variable RW Triangulum

Cited by in corpus (9)

• Variable Stars in Galactic Globular Clusters
• Stellar Exotica in 47 Tucanae
• Ultra-deep GEMINI near-infrared observations of the bulge globular cluster NGC 6624
• A BeppoSAX observation of Her X-1 during the first main-on after an anomalous low-state: evidence for rapid spin-down
• Cataclysmic and Close Binaries in Star Clusters. V. Erupting Dwarf Novae, Faint Blue Stars, X-ray sources, and the Classical Nova in the Core of M80
• Infrared Photometric Variability of GX13+1 and GX17+2
• Constraining the true nature of an exotic binary in the core of NGC 6624
• Cluster AgeS Experiment (CASE): Deficiency of observed dwarf novae in globular clusters
• Reevaluating the Origin of Detectable Cataclysmic Variables in Globular Clusters: Testing the Importance of Dynamics