Asteroseismic Calibration of the Rossby Number and Its Connection to the Stellar Dynamo and Fundamental Properties

Abstract The stellar Rossby number, a dimensionless parameter quantifying the influence of Coriolis forces on convective motions, plays a pivotal role in understanding magnetic stellar evolution. In this work, we explore the connection between the Rossby number and potential dynamo mechanisms in Sun-like stars, as well as its dependence on fundamental stellar properties. We present a novel, detailed asteroseismic calibration of the convective turnover time, incorporating for the first time Gaia photometry alongside surface gravity, effective temperature, and stellar metallicity. Our analysis employs an expanded sample of more than 150 stars, including targets from the Kepler LEGACY and Kepler Objects of Interest surveys, as well as more evolved stars observed by TESS and K2. This sample spans evolutionary stages from the main sequence to the early red giant branch, enabling a comprehensive investigation of Rossby number trends across stellar evolution.