See-coast: the Super-earth Explorer

Abstract

The Super-Earth Explorer Coronagraphic Off Axis Space Telescope (SEE-COAST) is a space mission concept to be submitted to ESA call for proposals. It is devoted to the direct imaging, in the visible, of the stellar light reflected by its planetary companion. Here we present the type of planetary characterization we may accomplish with SEE-COAST, and we include a brief description of the spacecraft and mission strategy. 1 Scientific objectives The main objective of the Super-Earth Explorer Coronagraphic Off Axis Space Telescope (SEE-COAST) is the characterization of a selected ensemble of exoplanets previously discovered by radial velocity and astrometric surveys. The project will be submitted to ESA call for proposals for small size missions to be launched in 2016. Several questions can be raised about exoplanets’ properties, some of them can be addressed by the detection of the stellar light reflected by the planet or of the thermal photons emitted by the planet. Both approaches are valid and may provide a complementary information. Of course, all questions may not be answered by a single mission. For some aspects we will have to wait for the second generation missions. The planetary properties we are interested in observing and constraining are: the size (mass and radius), the atmosphere (chemical composition, clouds, seasonal variations, thermal inertia), the surface (type -rocks, ice, water, “vegetation”-, inhomogeneities), rotation (period, atmospheric dynamics) and environment (rings). Reflected light and/or thermal emission may be used to study these planetary characteristics. The former approach relies on the information that can be extracted from the stellar light reflected by the planet as a function of different parameters: wavelength λ, polarization ~ P , time t. The planetary reflected flux can be written as: Fpl(λ, t, ~ P ) = A(λ, t, ~ P )F∗(λ, t) 4 (

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Cite this paper

@inproceedings{Schneider2007SeecoastTS, title={See-coast: the Super-earth Explorer}, author={Jean Schneider and Pierre Riaud and Giovanna Tinetti and Hans Martin Schmid and Daphne M. Stam and St{\'e}phane Udry and Pierre Baudoz and Olivier Grasset and Dimitri P. Mawet}, year={2007} }