On-line Workshop, October 25-28, 2021

The detection and characterization of extrasolar planets is a field that has undergone rapid advancements in the past decades. As we push towards the detection of lower-mass planets around Sun-like stars via both direct and indirect techniques our understanding of the host star becomes increasingly important.

Radial velocity and transit surveys are only now achieving the sensitivity necessary to detect low mass planets, and the signals are at a level comparable to or smaller than signals induced by magnetic activity on the stellar surface. Once a planet is detected, precise and accurate stellar parameters are needed in order to infer planetary masses and radii, which in turn yield bulk densities and compositions. At a population level, measurements of host star metallicity and abundances can be used to link stellar composition to the frequency, distribution and properties of planetary systems. Additionally, the presence of a stellar companion can be used to test theories of planet formation in dynamically active environments.

In this workshop we will cover the following topics:

• Fundamental stellar parameters that affect exoplanet detection/interpretation
• Stellar abundances and their effect on exoplanet formation
• Impact of stellar multiplicity on exoplanets
• Stellar activity effects on detecting exoplanets

We aim to identify what aspects of our understanding of stellar properties are limiting our ability to measure and characterize extrasolar planets, to present new ideas on how to overcome them, and to develop new collaborations between researchers studying extrasolar planets and those studying the properties of the stars they orbit.