August 11-15, 2014

Abstract

Method and tools for an objective approach of white dwarf asteroseismology

Stephane Charpinet (IRAP/OMP/Toulouse)

N. Giammichele (U. de Montréal), P. Brassard (U. de Montréal), V. Van Grootel (U. de Liège), & G. Fontaine (U. de Montréal)

Stellar oscillation modes propagate deep inside stars and carry on information potentially allowing us to reconstruct, through asteroseismology, parts of their internal structure and dynamics. We present and discuss here our strategy and tools developed to exploit objectively this potential for pulsating white dwarf stars. Our approach relies on a multimodal optimization technique aimed at identifying all potential seismic model solutions that best match the observed periods of a given star. This approach doesn't rely on model grids (hence avoiding their limitations) and makes use of static stellar structures of white dwarf stars as opposed to evolutionary models. The use of parameterized static models is a deliberate choice in this context and is aimed at approaching as closely as possible the real structure of the star as it is observed and probed by the detected oscillation modes without interferences from unavoidable model uncertainties propagated through billion years of evolution. We argue that this strategy is more likely to produce new tight constraints on the internal structure of white dwarf stars from which evolutionary models could be improved.

Mode of presentation: oral