2548109

Target RA (J2000): 26.632746 and deg Target Dec (J2000): 2.70057 and deg Gaia GMag: 9.395 Programme ID: CH_PR140078 Programme Manager: DEMANGEON PI of observing programme: Benz Title of programme: Axis 2 - Beyond Geometrical Albedo: A deeper understanding of the reflective behavior of exoplanet atmospheres (BENGAL) Abstract: Our knowledge of the reflective properties of exoplanet atmospheres is extremely limited outside of the Solar System planets. The geometric and Bond albedo measurements constitute the majority of the subjects observational constraints. Reflected light phase curves hold the key to gaining a better understanding of the fundamental scattering properties: single scattering albedo and asymmetry as well as determining the degree of inhomogeneity in the spatial distribution of clouds hazes and aerosols. However due to observational biases the vast majority of existing datasets that show a clear phase curve signal in the visible are aimed at hot gas giants. As a result they are plagued by the degeneracy between reflected and thermal light. Only Kepler-7 b was cool enough and Kepler sensitive enough to deliver a high precision phase curve that is dominated by reflected light. Kepler-7 b is thus the only exoplanet for which we have direct measurements of cloud distribution inhomogeneity and fundamental scattering properties. With this program we will leverage CHEOPS’ photometric precision bandpass and pointing flexibility to perform repeated phase curves observations of a few key targets. These canonical datasets will provide precise reflected light phase curves and will offer long-awaited counterparts to Kepler-7 b. We will investigate atmospheric inhomogeneity and measure fundamental scattering properties. We will begin to explore the d [truncated! Please see actual data for full text]