The rate of cooling of the pulsating white dwarf star G117-B15A: a new asteroseismological inference of the axion mass

A. H. CÓRSICO; L. G. ALTHAUS; M. M. MILLER BERTOLAMI; A. D. ROMERO; E. GARCÍA-BERRO; J. ISERN; S. O. KEPLER

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2012 vol. 424 p. 2792 - 2799

0035-8711

We employ a state-of-the-art asteroseismological model of G117−B15A, the archetype of theH-rich atmosphere (DA) white dwarf pulsators (also known as DAV or ZZ Ceti variables),and use the most recently measured value of the rate of period change for the dominant modeof this pulsating star to derive a new constraint on the mass of axion, the still conjecturalnon-baryonic particle considered as a candidate for dark matter of the Universe. Assumingthat G117−B15A is truly represented by our asteroseismological model, and, in particular,that the period of the dominant mode is associated with a pulsation g mode trapped in the Henvelope, we find strong indications of the existence of extra cooling in this star, compatiblewith emission of axions of mass ma cos2 β = 17.4+2.3−2.7 meV.