The more the merrier: grid based modelling of Kepler dwarfs with 5-dimensional stellar grids
Institute of Space Sciences (IEEC-CSIC), Campus UAB, E-08193, Barcelona, Spain
2 School of Physics and Astronomy, University of Birmingham, Edgbaston, B15 2TT, Birmingham United Kingdom
3 Stellar Astrophysics Centre, Dept. of Physics and Astronomy, Aarhus Univ., Ny Munkegade 120, DK-8000 Aarhus C, Denmark
4 Sydney Institute for Astronomy, School of Physics, University of Sydney, Sydney, Australia
5 SETI Institute, 189 Bernardo Avenue, CA 94043, Mountain View
⋆ e-mail: firstname.lastname@example.org
Published online: 27 October 2017
We present preliminary results of our grid based modelling (GBM) of the dwarf/subgiant sample of stars observed with Kepler including global asteroseismic parameters. GBM analysis in this work is based on a large grid of stellar models that is characterized by five independent parameters: model mass and age, initial metallicity (Zini), initial helium (Yini), and mixing length parameter (αMLT). Using this grid relaxes assumptions used in all previous GBM work where the initial composition is determined by a single parameter and that αMLT is fixed to a solar-calibrated value. The new grid allows us to study, for example, the impact of different galactic chemical enrichment models on the determination of stellar parameters such as mass radius and age. Also, it allows to include new results from stellar atmosphere models on αMLT in the GBM analysis in a simple manner. Alternatively, it can be tested if global asteroseismology is a useful tool to constraint our ignorance on quantities such as Yini and αMLT. Initial findings show that mass determination is robust with respect to freedom in the latter quantities, with a 4.4% maximum deviation for extreme assumptions regarding prior information on Yini – Zini relations and aMLT. On the other hand, tests carried out so far seem to indicate that global seismology does not have much power to constrain Yini – Zni relations of αMLT values without resourcing to additional information.
© Owned by the authors, published by EDP Sciences, 2017
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