Presentation #628.11 in the session Future Missions and Instrumentation.
Very little is known about the magnetic surface features of stars — particularly Sun-like stars — as nearly all stars are unresolved. The knowledge that we do have typically comes from rare syzygies with exoplanets, or are only large-scale features. To better understand the surface features of unresolved stars an extra dimension is typically required. Astrometry, a burgeoning exoplanet detection technique, is able to provide this extra dimension. At the wavelengths being proposed for astrometric missions — such as the upcoming TOLIMAN space telescope — the main surface features present are starspots which have a detectable impact on the photometric centroid of nearby stars. The long-term nature of astrometric missions allows for consistent stellar monitoring over many stellar rotation periods and starspot lifespans. Analysing this astrophysical signal can allow us to infer properties of the host star, such as relative inclination, magnitude and frequency of star-spots, differential rotation curves, and potentially the presence (or absence) of a Sun-like dynamo. This information can provide further information regarding the habitability of exoplanets. We demonstrate the feasibility of recovering these science products and advocate for the consideration of potential stellar physics results in astrometric mission design.