Observatoire de Paris Institut national de recherche scientifique français Univerité Pierre et Marie Curie Université Paris Diderot - Paris 7

Directly imaging cold and temperate exoplanets in reflected starlight : atmospheric characterization and target selection

mardi 22 novembre 2022, par Oscar Carrion (LESIA)

Lundi 21 novembre 2022 à 16h00 , Lieu : Salle de conférence du bâtiment 17

With more than five thousand exoplanets discovered to date, the next milestone is the atmospheric characterization of a significant number of these worlds. The observing techniques that are currently available have biased the discovery and atmospheric characterization of exoplanets towards hot, giant planets on short-period orbits. Direct-imaging observations will be needed to overcome these biases and enable the analysis of cold and temperate long-period exoplanets and their atmospheres.

Studying this population of planets, which has remained out of reach thus far, is a key to understand the diversity of exoplanets and, in particular, the existence of habitable conditions beyond the Earth. Direct-imaging observations of temperate exoplanets have indeed been identified as a scientific priority for the coming decades both by the US Astro 2020 Decadal Survey and by the ESA Voyage 2050 report. In this talk we address the physical fundamentals of direct-imaging observations in reflected starlight, and derive practical conclusions for the planning and interpretation of the upcoming measurements.

We also analyse the prospects for atmospheric characterization of exoplanets from reflected-starlight spectra with different observing strategies. Finally, we compute which of the known exoplanets are potentially observable with several upcoming direct-imaging space telescopes, and discuss some interesting science cases.