Albedo of exoplanets constrained by polarimetry

Polarimetry is a novel and powerful technique for detecting directly starlight scattered in a planetary atmosphere and inferring information on its geometry, chemistry, and thermodynamics. Recently, we have started a polarimetric survey of nearby planetary systems with hot Jupiters closely orbiting their host stars. We have demonstrated how polarized scattered light reveals reflecting properties of exoplanets and provides direct probes of their atmospheres. We find good consistency of our results with photometric, spectroscopic, and other polarimetric measurements. Altogether they indicate the dominance of Rayleigh scattering in the optical and high albedos in the blue for some hot Jupiters.