Connecting Granulation and Magnetic Activity in Radial Velocities: The Next Breakthrough for High-Precision Spectroscopy

Stellar variability is now the dominant obstacle to achieving the radial velocity (RV) precision required to detect and characterize Earth-like exoplanets. While oscillations and magnetic activity have been partially mitigated, convective granulation and its interaction with magnetic fields remain among the least understood sources of RV variability.

To tackle this, the splinter session 'Connecting Granulation and Magnetic Activity in Radial Velocities: The Next Breakthrough for High-Precision Spectroscopy' was organized at Cool Stars 23, bringing together researchers in observations, numerical simulations, and data-driven techniques. The discussions highlighted several priorities: combining physically motivated models with data-driven approaches, developing standardized benchmark datasets, and validating simulations against high-quality observations across a range of stellar types.

Participants also emphasized the need for coordinated observing strategies, improved characterization of individual spectral lines, and physically informed line-by-line analyses to disentangle convective and magnetic signals. The resulting summary outlines the key challenges that must be addressed to reach the sub-40 cm/s precision required for the next generation of RV planet searches.