Marek Biesiada(Katowice):

Pulsating white dwarfs as a tool for astroparticle physics

Abstract:

Nonstandard theories of fundamental interactions typically predict the existence of new kinds of weakly interacting particles. These can escape freely from stellar interiors and act as additional source of cooling. Considerable agreement of a variety of astrophysical observations with standard physics can serve as a source of constraints on non-standard ideas. In this talk we consider G117-B15A pulsating white dwarf for which the secular rate, at which the period of its fundamental mode increases, has been accurately measured. This star has been claimed the most stable oscillator ever recorded in the optical band. Because an additional channel of energy loss would speed up the cooling rate, one is able to use this stability to derive a bound on exotic particles as well as a bound on temporal variability of gravitational constant.

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