Seminars

On the determination of stellar ages, masses and radii from theoretical models
Andrea Bonfanti (STAR)

Salle de réunion AGO (local -1/14), Institut d'Astrophysique et de Géophysique
Bâtiment B5c, Quartier Agora, Allée du 6 Août, 19C, B-4000 Liège 1 (Sart-Tilman)

Determining the ages of stars is a very challenging task. Several indicators are available, but no single method works well for a broad range of spectral type or for each evolutionary phase of a star. My PhD project was related to the building of an algorithm for the determination of stellar ages, considering evolutionary tracks and isochrones. This model-dependent approach, which has been complemented by using gyrochronology, stellar magnetic activity and scaling relations coming from asteroseismology, also enables to retrieve other useful stellar parameters such as radius or mass. Here I will briefly discuss the problems of inferring ages from theoretical models and the characterization of solar-type stars of the solar neighbourhood, with a specific attention to the realistic uncertainties to be attributed to the main stellar parameters as a sum of internal and model-related ones. Moreover, considering that the determination of exoplanet properties requires the knowledge of stellar parameters, I will also show you the synergy between the characterization of stars and the exoplanetary science with particular references to the future Cheops mission and the analysis of stellar light curves.


Coffee, tea and cookies will be served after the seminar...