Orbital periods of cataclysmic variables identified by the SDSS. IV. SDSS J220553.98+115553.7 has stopped pulsating

Abstract

We present time-series VLT spectroscopy and NTT photometry of the cataclysmic variable SDSS J220553.98+115553.7, which contains a pulsating white dwarf. We determine a spectroscopic orbital period of 82.825 +/- 0.089 min from velocity measurements of the Halpha emission line. A period analysis of the light curves reveals a dominant periodicity at 44.779 +/- 0.038 min which is not related to the spectroscopic period. However, the light curves do not exhibit a variation at any frequency which is attributable to GW Lib type pulsations, to a detection limit of 5 mmag. This non-detection is in contrast to previous studies which have found three pulsation frequencies with amplitudes of 9 to 11 mmag at optical wavelengths. Destructive interference and changes to the thermal properties of the driving layer in direct response to accretion can be ruled out as causes of the non-detection. Alternatively, it is feasible that the object has cooled out of the instability strip since a previous (unobserved) dwarf nova superoutburst. This would be the first time this behaviour has been seen in a cataclysmic variable pulsator. Another possibility is that changes in the surface characteristics, possibly induced by accretion phenomena, have modified the surface visibility of the pulsation modes. Further observations, particularly improved constraints on the timescale for changes in the mode spectrum, are needed to distinguish among possible explanations.

arXiv commentAccepted for publication in MNRAS; 7 pages and 6 figures. The data will be available from http://www.astro.keele.ac.uk/~jkt

References in corpus (28)

• The Sloan Digital Sky Survey: Technical Summary
• The SDSS View of the Palomar-Green Bright Quasar Survey
• The Donor Stars of Cataclysmic Variables
• 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
• Gravity-Modes in ZZ Ceti Stars: I.Quasiadiabatic Analysis of Overstability
• Absolute dimensions of detached eclipsing binaries. I. The metallic-lined system WW Aurigae
• Measuring White Dwarf Accretion Rates via their Effective Temperatures
• HS2331+3905: The cataclysmic variable that has it all
• Eclipsing binaries in open clusters. I. V615 Per and V618 Per in h Per
• Towards an Empirical Determination of the ZZ Ceti Instability Strip
• HST Spectra of GW Librae: A Hot Pulsating White Dwarf in a Cataclysmic Variable
• The Nonradially-Pulsating Primary of the Cataclysmic Variable GW Librae
• Pulsational Instabilities in Accreting White Dwarfs
• VLT/FORS spectroscopy of faint cataclysmic variables discovered by the Sloan Digital Sky Survey
• Re-defining the Empirical ZZ Ceti Instability Strip
• A ZZ Ceti white dwarf in SDSS J133941.11+484727.5
• Orbital periods of cataclysmic variables identified by the SDSS. III. Time-series photometry obtained during the 2004/5 International Time Project on La Palma
• HST/STIS Spectroscopy and Modeling of the Long Term Cooling of WZ Sagittae following the July 2001 Outburst
• Discovery of eleven new ZZ Ceti stars
• White Dwarf Heating and Subsequent Cooling in Dwarf Nova Outbursts
• Seismology of the Accreting White Dwarf in GW Lib
• Orbital periods of cataclysmic variables identified by the SDSS. II. Measurements for six objects, including two eclipsing systems
• WZ Sge: HST Spectroscopy of the Cooling of the White Dwarf after the 2001 Outburst
• SDSS J233325.92+152222.1 and the evolution of intermediate polars
• HST and Optical Observations of Three Pulsating Accreting White Dwarfs in Cataclysmic Variables
• A 2.09-h Photometric Periodicity in GW Librae

Cited by in corpus (11)

• SDSS unveils a population of intrinsically faint cataclysmic variables at the minimum orbital period
• Evidence for reduced magnetic braking in polars from binary population models
• Finding the Instability Strip for Accreting Pulsating White Dwarfs from HST and Optical Observations
• Orbital periods of cataclysmic variables identified by the SDSS. VI. The 4.5-hr period eclipsing system SDSS J100658.40+233724.4
• Orbital periods of cataclysmic variables identified by the SDSS. V. VLT, NTT and Magellan observations of nine equatorial systems
• Orbital periods of cataclysmic variables identified by the SDSS. VII. Four new eclipsing systems
• Orbital periods of cataclysmic variables identified by the SDSS. IX. NTT photometry of eight eclipsing and three magnetic systems
• The white dwarf in dwarf nova SDSS J080434.20+510349.2: Entering the instability strip?
• R-mode oscillations in accreting white dwarfs in cataclysmic variables
• Orbital periods of cataclysmic variables identified by the SDSS. VIII. A slingshot prominence in SDSS J003941.06+005427.5?
• The fainter the better: cataclysmic variable stars from the SDSS