Laura Venuti

Preparing for EVE: multi-wavelength monitoring of young, accreting stars to trace the inner structure of their protoplanetary disks

Over the first few million years of a star’s life, its evolution is governed by the dynamics of mass accretion from the inner regions of the surrounding protoplanetary disk. This process has a long-lasting impact on key stellar properties like mass and rotation rate, and it shapes the structure of the inner disk at the epoch of planet formation and migration. A key parameter to predict the evolution of the star-disk system is the radial distance between the stellar surface and the inner disk edge, which sets a physical limit to the innermost planets’ orbits. However, the location of this inner disk radius is hard to constrain observationally, for all except the closest young stars. Here, I discuss a first, widely-accessible photometric diagnostics to infer the inner disk structure around individual young stars by combining time domain measurements of stellar luminosities at optical and near-ultraviolet wavelengths with state-of-the-art simulations of disk accretion onto young stars. I also present the Early eVolution Explorer (EVE), a new NASA Small Explorer mission concept that is being developed by an international team of researchers between the USA, Europe, and Australia. Dedicated to polychromatic time domain surveys of young star clusters, EVE will investigate the earliest stages in the co-evolution of stars and planets, to determine the role played by disk accretion in setting stellar activity levels and the early architecture of planetary systems.