The gravitational wave radiation of pulsating white dwarfs revisited: the case of BPM 37093 and PG 1159-035

¹ Departament de Física Aplicada, Universitat Politècnica de Catalunya, Av. del Canal Olímpic, s/n, 08860, Castelldefels, Barcelona, Spain e-mail: [garcia;loren;leandro]@fa.upc.edu
² Institut d'Estudis Espacials de Catalunya, Ed. Nexus, c/Gran Capità 2, 08034, Barcelona, Spain e-mail: [lobo;isern]@ieec.fcr.es
³ Institut de Ciències de l'Espai, C.S.I.C., Campus UAB, Facultat de Ciències, Torre C-5, 08193 Bellaterra, Spain
⁴ Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, Paseo del Bosque s/n, (B1900FWA) La Plata, Argentina e-mail: acorsico@fcaglp.unlp.edu.ar
⁵ Instituto de Astrofísica La Plata, IALP, CONICET-UNLP, Argentina

Received: 6 July 2005
Accepted: 9 September 2005

Abstract

We compute the emission of gravitational radiation from pulsating white dwarfs. This is done by using an up-to-date stellar evolutionary code coupled with a state-of-the-art pulsational code. The emission of gravitational waves is computed for a standard white dwarf with a liquid carbon-oxygen core and a hydrogen-rich envelope, for a massive DA white dwarf with a partially crystallized core for which various modes have been observed (BPM 37093) and for PG 1159-035, the prototype of the GW Vir class of variable stars, for which several quadrupole modes have been observed as well. We find that these stars do not radiate sizeable amounts of gravitational waves through their observed pulsation g-modes, in line with previous studies. We also explore the possibility of detecting gravitational waves radiated by the f-mode and the p-modes. We find that in this case the gravitational wave signal is very large and, hence, the modes decay very rapidly. We also discuss the possible implications of our calculations for the detection of gravitational waves from pulsating white dwarfs within the framework of future space-borne interferometers like LISA.