Discovery of ZZ Cetis in detached white dwarf plus main-sequence binaries

TL;DR

This study reports the discovery of pulsating white dwarfs in detached WD+MS binaries, including the first such pulsator with a main-sequence companion, providing new insights into binary evolution effects on white dwarf structure.

Contribution

First detection of pulsating white dwarfs in detached WD+MS binaries, including the first pulsator with a main-sequence companion in a post common envelope binary.

Findings

Pulsations detected in 7 out of 26 systems

First pulsating WD with a main-sequence companion in a post common envelope binary

Discovered a partially eclipsing system, SDSSJ1223-0056

Abstract

We present the first results of a dedicated search for pulsating white dwarfs (WDs) in detached white dwarf plus main-sequence binaries. Candidate systems were selected from a catalogue of WD+MS binaries, based on the surface gravities and effective temperatures of the WDs. We observed a total of 26 systems using ULTRACAM mounted on ESO's 3.5m New Technology Telescope (NTT) at La Silla. Our photometric observations reveal pulsations in seven WDs of our sample, including the first pulsating white dwarf with a main-sequence companion in a post common envelope binary, SDSSJ1136+0409. Asteroseismology of these new pulsating systems will provide crucial insight into how binary interactions, particularly the common envelope phase, affect the internal structure and evolution of WDs. In addition, our observations have revealed the partially eclipsing nature of one of our targets, SDSSJ1223-0056.