Discovery of two new accreting pulsating white dwarf stars

TL;DR

This paper reports the discovery of two new accreting pulsating white dwarf stars in cataclysmic variables, expanding the known population and providing insights into their pulsation periods and behaviors.

Contribution

It introduces two newly identified accreting pulsating white dwarfs and discusses their pulsation characteristics, adding valuable data to the study of such stars.

Findings

Discovered two new accreting pulsating white dwarfs.

Identified pulsation periods of approximately 1230s and 260s.

Expanded the total known accreting white dwarf pulsators to eleven.

Abstract

We report the discovery of two new accreting pulsating white dwarf stars amongst the cataclysmic variables of the Sloan Digital Sky Survey: SDSSJ074531.91+453829.5 and SDSSJ091945.10+085710.0. We observe high amplitude non-sinusoidal variations of 4.5-7% at a period close to 1230s in the optical light curves of SDSSJ074531.91+453829.5 and a low amplitude variation of 0.7-1.6% near 260s in the light curves of SDSSJ091945.10+085710.0. We infer that these optical variations are a consequence of nonradial g-mode pulsations in the accreting primary white dwarfs of these cataclysmic variables. However we cannot rule out the remote possibility that the 260s period could be the spin period of the accreting white dwarf SDSSJ091945.10+085710.0. We also uncovered a non-variable SDSSJ171145.08+301320.0 during our search; our two observing runs exclude any pulsation related periodicities in the range of 85-1400s with an amplitude greater than or equal to 0.5%. This discovery paper brings the total number of known accreting white dwarf pulsators to eleven.