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SAC Seminar - Christian Sahlholdt: Accurate stellar parameters in the era of large surveys

Oplysninger om arrangementet

Tidspunkt

torsdag 10. januar 2019,  kl. 14:15 - 15:00

Sted

1520-616

Next SAC Seminar will be held by Christian Sahlholdt from Lund University.

Title: Accurate stellar parameters in the era of large surveys

Abstract: We are currently transitioning into a new era of stellar and Galactic astronomy thanks to the many ongoing and future large-scale stellar surveys. With astrometry from the Gaia mission, ground-based spectroscopy, and time-series photometry from space missions such as Kepler and TESS, a wide range of stellar parameters can be estimated for millions of stars. With such large samples, the parameter estimation is usually automated and now often based on machine learning algorithms. To limit biases in the stellar parameters, it is important to have smaller reference samples of stars with accurately known parameters for use as validation and, potentially, calibration. I will present my work on testing the accuracy and limitations of two stellar parameters: 1) radii of the dwarf stars in the Kepler asteroseismic LEGACY sample, and 2) isochrone-based ages of the Gaia FGK benchmark stars. In addition to the age study of the Gaia benchmark stars, I will present a work in progress on testing age determination of stars in open clusters when treated as field stars.