IA/U.Porto Cookie Seminar - Impact of an Interferometric radius on modeling bright stars - 20 setembro 2017



Benard Nsamba




The interferometric radius of a star acts as an additional observational constraint which can be used in optimization procedures of asteroseismic forward modeling. We assess the precision on interferometric radius needed to yield stellar model parameters with high precision and accuracy. To this end, we make use of Alpha Centauri and solar-type stars for which interferometric radius measurements are available. Asteroseismic data from ground-based observations are available for both components of Alpha Centauri whereas our solar-type stars have long-baseline photometry from the Kepler telescope. Using state-of-the-art asteroseismic tools, we demonstrate that for Alpha Centauri A, we need an interferometric radius precision to be less than 1% inorder to yield a stellar mass with a precision of about 1%. In addition, we find the best fitting models that reproduce the revised observed mass of Alpha Centauri A (Pourbaix et al. 2016) to suggest a convective core contrary to the models that fit previous observation by Pourbaix et al. 2002 and Kervella et al. 2016. Our results also show that interferometric radius with a precision above 2% yield no improvement on the precision of the derived stellar mass.
20 de setembro de 2017 | 13:30
Centro de Astrofísica da Universidade do Porto (Classroom)
Rua das Estrelas, 4150-762 Porto
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