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Evolution of magnetic activity of solar-like stars with age

Savita Mathur
Instituto de Astrofísica de Canarias, Tenerife, Spain

It is known that for a star like the Sun, rotation and magnetic activity evolve with age. Indeed, In 1972, Skumanich showed that on the main sequence, a solar-like star spins down and becomes less active magnetically with age. This evolution opened the possibility to use rotation and magnetic activity as a stellar clock. While many surveys studied the magnetic activity of stars with spectroscopy and spectropolarimetry, the sample is still small with up to a few thousands of stars.
The recent catalog of rotation periods and photometric magnetic activity proxies for more than 55,000 stars observed by the Kepler mission is a goldmine to study the evolution of magnetic activity of solar-like stars. In this talk I will present the investigation to find relations between Sph, a photometric magnetic activity index, stellar ages as well as other stellar fundamental parameters (such as luminosity, metallicity, rotation periods). Such analysis is based on two different methods: a Bayesian fit of analytical relations and a Random Forest algorithm. Promising results are found to predict ages using these methods with up to 5-6% median differences between the predictions and the stellar models.

2023 March 20, 13:30

Centro de Astrofísica da Universidade do Porto (Auditorium)
Rua das Estrelas, 4150-762 Porto

Faculdade de Ciências da Universidade de Lisboa Universidade do Porto Faculdade de Ciências e Tecnologia da Universidade de Coimbra
Fundação para a Ciência e a Tecnologia COMPETE 2020 PORTUGAL 2020 União Europeia