Articulo
An independent constraint on the secular rate of variation of the gravitational constant from pulsating white dwarfs
Autor
Córsico, Alejandro Hugo
Althaus, Leandro Gabriel
García Berro, Enrique
Romero, Alejandra Daniela
Institución
Resumen
A secular variation of the gravitational constant modifies the structure and evolutionary time scales of white dwarfs. Using an state-of-the-art stellar evolutionary code and an up-to-date pulsational code we compute the effects of a secularly varying G on the pulsational properties of variable white dwarfs. Comparing the the theoretical results obtained taking into account the effects of a running G with the observed periods and measured rates of change of the periods of two well studied pulsating white dwarfs, G117-B15A and R548, we place constraints on the rate of variation of Newton's constant. We derive an upper bound Ġ/G ~ −1.8 × 10−10 yr−1 using the variable white dwarf G117-B15A, and Ġ/G ~ −1.3 × 10−10 yr−1 using R548. Although these upper limits are currently less restrictive than those obtained using other techniques, they can be improved in a future measuring the rate of change of the period of massive white dwarfs.
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