How exoplanets are affected by their host stars
|Date||25 September 2019|
In this talk I will overview the recent works on magnetism of cool, main-sequence stars, their winds and impact on surrounding exoplanets. The winds of these stars are very tenuous and persist during their lifetime. Although carrying just a small fraction of the stellar mass, these winds regulate the rotation of the star and can affect surrounding exoplanets. Because they are incredibly tenuous, wind detection has been a very challenging task. Numerical models are therefore an important tool to grasp a better understanding of cool stars’ winds. Our numerical simulations include observationally-derived surface magnetic field maps, which are necessary given the key effects of magnetic fields on stellar winds. Since cool stars are generally surrounded by exoplanets, understanding their stellar winds is a key step towards characterisation of exoplanetary environments. Although these environments may be potentially dangerous for a planet's atmosphere, the interaction between exoplanets and the host-star winds can provide other avenues for planet detection and even assess exoplanetary properties, which would otherwise remain unknown.