A DWARF NOVA IN THE GLOBULAR CLUSTER M13
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-67, Cambridge, MA 02138 (United States)
- Universite de Toulouse, Universite Paul Sabatier-Observatoire Midi-Pyrenees, Institut de Recherche en Astrophysique et Planetologie (IRAP), Toulouse (France)
- Department of Physics and Astronomy, The Open University, Walton Hall, Milton Keynes, MK7 6AA (United Kingdom)
- Department of Physics, University of Southampton, Southampton, S017 1BJ (United Kingdom)
Dwarf novae (DNe) in globular clusters (GCs) seem to be rare with only 13 detections in the 157 known Galactic GCs. We report the identification of a new DN in M13, the 14th DN identified in a GC to date. Using the 2 m Faulkes Telescope North, we conducted a search for stars in M13 that show variability over a year (2005-2006) on timescales of days and months. This led to the detection of one DN showing several outbursts. A Chandra X-ray source is coincident with this DN and shows both a spectrum and variability consistent with that expected from a DN, thus supporting the identification. We searched for a counterpart in Hubble Space Telescope Advanced Camera for Surveys/Wide Field Camera archived images and found at least 11 candidates, of which we could characterize only the 7 brightest, including one with a 3{sigma} H{alpha} excess and a faint blue star. The detection of one DN when more could have been expected likely indicates that our knowledge of the global Galactic population of cataclysmic variables is too limited. The proportion of DNe may be lower than found in catalogs, or they may have a much smaller mean duty cycle ({approx}1%) as proposed by some population synthesis models and recent observations in the field.
- OSTI ID:
- 21576725
- Journal Information:
- Astrophysical Journal, Vol. 733, Issue 2; Other Information: DOI: 10.1088/0004-637X/733/2/106; ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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