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Spectral and Polarimetric characterization of Gaseous and Telluric planets with SEE COAST.
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Spectral and Polarimetric characterization of Gaseous and Telluric planets with SEE COAST ULg / CSL / LESIA / LUTH / LUAN / ETH-Zurich / IAP / Obs. Geneva / U. Bern / UCL / ROE / U. Hertfords. / MSSL / SRON / Astron / U. Utrecht / LAOG / ONERA / DLR / U. Vienna / U. Nantes / U. Torino / Astrium A. Boccaletti (Paris Observatory) P. Baudoz, D. Mawet, J. Schneider, G. Tinetti, R. Galicher, C. Cavarroc J. Hough, P. Doel, D. Pinfield, C.-U. Keller, J.-L. Beuzit, S. Udry, M. Ferrari, E. Martin, F. Ménard , E. Sein, & SEE COAST Team …
HST Darwin/TPF-I MIR: Earth TPF-C Vis: Earth JWST NIR + MIR: Old EGPs 4m + OA Silla, CFH 30/42m + XAO EPICS/ELTs NIR : EGPs intermediate Old + Super-Earth ? 8m + XAO SPHERE / GPI / HiCIAO NIR : EGPs young/massive/nearby 8m + OA VLT, Keck, Gemini, Subaru Direct Imaging Programs Overview Space-based Opportunity for Space projects SEE COAST Vis/NIR: Old Jupiter + Super Earth In the Visible mature giants & Super-Earths 1995 2000 2008 2011 2017-2020 >2025-30 Ground-based
We already have targets !!! From radial velocity surveys : From direct imaging :
More targets to come • We can anticipate many RV planets at longer periods (giants and tellurics) • A few accessible from SPHERE/GPI/HiCIAO(1. - 2.3 mm) and JWST (2.5 - 28 mm) • Motivation for exploring a different spectral range (in the visible) • angular resolution AND contrast are required: • A small telescope in space can be optimized for exo-planetology • "Super Earth" as a sweet spot : brighter, earth-like notions apply (atmosphere, climate, variations, habitability, …) • What sort of astrophysics on these planets ?
- Spectra => Chemical composition - Rayleigh scatterring => pressure, surf. reflectivity Burrows, Sudarsky Explore the Diversity with SEE COAST • Spectroscopy
- Polarization => Clouds / albedo Jupiter-like planet - Stam et al. 2005 Earth-like planet - Stam et al. 2008 A=0 ocean vegetation cloud A=1 Explore the Diversity • Spectroscopy • Polarimetry
Cloud free Earth from 0.65 to 0.9 m 0.75 m - Spectral time variation => variation of temperature => surface properties 130° • Polarimetric time variation • => surface properties 0.45 m 90° 50° Phase angle Explore the Diversity • Spectroscopy • Polarimetry • Variability
Which targets ? (contrast + IWA requirements) short wavelengths are optimal 10-10 contrast required longer wavelengths require small IWA coronagraph (2l/D) • near IR (1 - 1.2 mm) • self luminous planets • T > 800K
4,85 m long Hyperbolic secondary mirror Two folding mirrors Focal plane Parabolic primary mirror A proposal to Cosmic Vision … • Submitted in 2007 to ESA Cosmic Vision
Coronagraphy: Multi 4QPM N phase masks in series => Improves bandwidth as ^N Pupil Baudoz et al. 2007, 08 FQPM Module # 1 Multi 4QPM : Meudon Telescope laboratory planet Contrast :6.7 10-9 bandwidth 20%
Wavefront correction : Coherence Speckle nulling in a limited FOV with a DM (JPL)
Summary SEE COAST requires : • High contrast : ≈ 10-10AND small IWA : ≈ 2 l/D SEE COAST can get : • low res spectra of mature giants < 20pc (< 8 - 10 AU) • colors of a few mature Super Earths < 10pc (< 4 - 5 AU) • possibly Earths around the nearest star (a Cen) • low res spectra of self luminous planets (extension to near IR) SEE COAST is : • Compatible with general astrophysics (pushing to UV, wide field ?) • Compatible with transit spectroscopy • additional targets (unresolved planets) & complements IR transit characterization programs Next steps in the project : • refine some science cases and simulations (statistical analysis) • elaborate optical design with industrial partners (Astrium) + derive tolerances • technological developments in coronagraphy and wavefront control • get prepared for next COSMIC VISION proposal (2010)