Novae/Cataclysmic Variables

182.07

Accreting Pulsating White Dwarfs: Hotter than Single DAVs

10. Cataclysmic Variables, Novae, Supernovae, Wolf-Rayet Phenomena

Paula Szkody¹, A. Mukadam¹, B. T. Gaensicke², P. A. Woudt³, J. Solheim⁴, E. M. Sion⁵, A. Nitta⁶, B. Warner³, D. K. Sahu⁷, T. Prabhu⁷, A. Henden^8
1Univ. of Washington, ²Univ. of Warwick, United Kingdom, ³Univ. of Cape Town, South Africa, ⁴Institute of Theoretical Astrophysics, Norway, ⁵Villanova University, ⁶Gemini Observatory, ⁷Indian Institute of Theoretical Astrophysics, India, ⁸AAVSO.

Single DAV pulsating white dwarfs are known to show non-radial g-mode pulsations with periods around 50-1400s and have temperatures in the specific range of 11,000-12,500K. With the discovery of several pulsating white dwarfs in the accreting close binary systems of cataclysmic variables, it is possible to probe the effects of mass transfer and accretion, external heat input, He enriched envelopes and fast rotation on the location of the instability strip. Our UV observations of three pulsating accreting white dwarfs in the cataclysmic variables SDSSJ013132-0901, SDSSJ161033-0102 and SDSSJ220553+1155 with the Solar Blind Channel on HST show enhanced pulsation amplitudes over the optical and white dwarf temperatures near 15,000K. Combined with temperatures of two other known accreting pulsators (GW Lib and HS2331+3905), it appears that there is a wide range in the instability strip for accreting pulsators. This range may be due to different white dwarf masses or compositions compared to single DAVs. This research was supported by NASA grant GO-10233.01A from STScI.