New Pulsating White Dwarfs in Cataclysmic Variables

Abstract

The number of discovered non-radially pulsating white dwarfs (WDs) in cataclysmic variables (CVs) is increasing rapidly by the aid of the Sloan Digital Sky Survey (SDSS). We performed photometric observations of two additional objects, SDSS J133941.11+484727.5 (SDSS 1339), independently discovered as a pulsator by Gansicke et al., and SDSS J151413.72+454911.9, which we identified as a CV/ZZ Ceti hybrid. In this Letter we present the results of the remote observations of these targets performed with the Nordic Optical Telescope (NOT) during the Nordic-Baltic Research School at Moletai Observatory, and follow-up observations executed by NOT in service mode. We also present 3 candidates we found to be non-pulsating. The results of our observations show that the main pulsation frequencies agree with those found in previous CV/ZZ Ceti hybrids, but specifically for SDSS 1339 the principal period differs slightly between individual observations and also from the recent independent observation by Gansicke et al. Analysis of SDSS colour data for the small sample of pulsating and non-pulsating CV/ZZ Ceti hybrids found so far, seems to indicate that the r-i colour could be a good marker for the instability strip of this class of pulsating WDs.

5 pages, 6 figures, 2 tables, accepted for publication in MNRAS Letters

References in corpus (9)

• Cataclysmic Variables from SDSS II. The Second Year
• Theoretical Modeling of the Thermal State of Accreting White Dwarfs Undergoing Classical Novae
• Cataclysmic Variables from SDSS I. The First Results
• HS2331+3905: The cataclysmic variable that has it all
• The Nonradially-Pulsating Primary of the Cataclysmic Variable GW Librae
• A ZZ Ceti white dwarf in SDSS J133941.11+484727.5
• Seismology of the Accreting White Dwarf in GW Lib
• SDSS J161033.64-010223.3: A second Cataclysmic Variable with a Non-radially Pulsating Primary
• Mode Identification from Combination Frequency Amplitudes in ZZ Ceti Stars

Cited by in corpus (10)

• Pulsating White Dwarf Stars and Precision Asteroseismology
• SDSS unveils a population of intrinsically faint cataclysmic variables at the minimum orbital period
• Orbital periods of cataclysmic variables identified by the SDSS. III. Time-series photometry obtained during the 2004/5 International Time Project on La Palma
• Finding the Instability Strip for Accreting Pulsating White Dwarfs from HST and Optical Observations
• Discovery of two new accreting pulsating white dwarf stars
• HST and Optical Observations of Three Pulsating Accreting White Dwarfs in Cataclysmic Variables
• Multi-site Observations of Pulsation in the Accreting White Dwarf SDSS J161033.64-010223.3 (V386 Ser)
• R-mode oscillations in accreting white dwarfs in cataclysmic variables
• NGTS and HST insights into the long period modulation in GW Librae
• An observer's view on the future of asteroseismology