From the Sun to stars: Learning from the solar paradigm

Since the first detection of a planet that orbits a star similar to the Sun in the early 1990’s, the field of exoplanet research has gathered a lot of interest from both the scientific community and the general public. Dedicated planet hunting missions of the past, like Kepler, have found several thousands of planets orbiting stars similar as the Sun, and with the start of the James Webb Telescope and its first observations, we are entering a new era where we are not only able to detect exoplanets but measure their atmospheres directly, giving hope to find tracers of life on other planets.

However, the host stars of planets make the interpretation of exoplanet signals difficult. Stellar activity, whether caused by manifestations of stellar magnetic fields in the the form of cool regions (star spots) and bright regions (faculae) on the surfaces of the stars or by stellar “flicker,” mimics and hides exoplanet signals and pollutes measurements of planetary atmospheres. Accurate modelling and removal of the stellar signal are therefore vital in order to properly characterise exoplanets.

The Sun provides the ideal benchmark for any modelling approaches, especially when studying the connection between surface magnetic activity and its imprints in observables. In this talk, I will present modelling efforts in explaining both solar- and stellar-brightness variations by following the path of extending the solar paradigm to stars with higher activity and rotation rates. I will present current state-of-the-art modelling approaches and how solar data can be further exploited to understand signatures of stellar activity in observations.