Polarimetry and spectral imaging of mature Jupiter and super-earth with SEE-COAST

Transcription

1 Polarimetry and spectral imaging of mature Jupiter and super-earth with SEE-COAST Jean Schneider, A. Boccaletti, P. Baudoz, R. Galicher, R. Gratton, D. Stam et al. & E. Pantin,

2 Complementarity of techniques Transit SPECTRA & POLARIZATION DATA Direct imaging

3 Ground/space complementarity We are here Space-based > Ground-based

4 Ground/space complementarity HST We are here Space-based > m + OA Silla, CFH 8m + OA VLT, Keck, Gemini Ground-based

5 Ground/space complementarity HST We are here Space-based > m + OA Silla, CFH 8m + OA VLT, Keck, Gemini 8m + XAO SPHERE / GPI / HICIAO NIR : EGPs young/massive/nearby Ground-based

6 Ground/space complementarity HST We are here Space-based > m + OA Silla, CFH 8m + OA VLT, Keck, Gemini 8m + XAO SPHERE / GPI / HICIAO NIR : EGPs young/massive/nearby 30/42m + XAO EPICS, METIS etc with ELTs NIR : EGPs intermediate Old + Super-Earth? Ground-based

7 Ground/space complementarity HST We are here Space-based SPICA MIR: Old EGPs JWST NIR + MIR: Old EGPs > m + OA Silla, CFH 8m + OA VLT, Keck, Gemini 8m + XAO SPHERE / GPI / HICIAO NIR : EGPs young/massive/nearby 30/42m + XAO EPICS, METIS etc with ELTs NIR : EGPs intermediate Old + Super-Earth? Ground-based

8 Ground/space complementarity We are here HST Space-based? SPICA MIR: Darwin/TPF-I Old EGPs MIR: Earth TPF-C Vis: Earth JWST? NIR + MIR: Old EGPs m + OA Silla, CFH > m + OA 8m + XAO 30/42m + XAO VLT, Keck, SPHERE / GPI / HICIAO EPICS, METIS, etc with ELTs Gemini NIR : EGPs young/massive/nearby NIR : EGPs intermediate Old + Super-Earth? Ground-based SEE-COAST UCF Orlando 8

9 Ground/space complementarity We are here HST? Space-based SPICA MIR: Darwin/TPF-I Old EGPs Opportunity for space projects NIR + MIR: Old EGPs m + OA Silla, CFH TPF-C Vis: Earth Visible light JWST MIR: Earth Old giants & super-earths ? > m + OA 8m + XAO 30/42m + XAO VLT, Keck, SPHERE / GPI / HICIAO EPICS, METIS, etc with ELTs Gemini? NIR : EGPs young/massive/nearby NIR : EGPs intermediate Old + Super-Earth? Ground-based SEE-COAST UCF Orlando 9

10 Ground/space complementarity We are here HST Space-based? SPICA MIR: Old EGPs Darwin/TPF-I MIR: Earth TPF-C Vis: Earth JWST m + OA Silla, CFH NIR + MIR: SEE COAST Vis/NIR Old EGPs Old Jupiter + Super Earth > m + OA 8m + XAO 30/42m + XAO VLT, Keck, SPHERE / GPI / HICIAO EPICS, PFI, etc with ELTs Gemini? NIR : EGPs intermediate NIR : EGPs young/massive/nearby Old + Super-Earth? Ground-based SEE-COAST UCF Orlando 10

11 What SEE-COAST will characterize : What's expected : Mature Jupiter (>1 Gyr) Super - Earth Brighter Atmosphere, climate Variations, habitability Around nearby star Exo-zodiacal and debris disk And unexpected objects! Stay open-minded (cf. hot Jupiter in 1995)

12 Spectroscopy : chemical composition Solid planets Giant planets

13 Polarimetry : physical informations Jupiter-like planet - Stam et al Earth-like planet - Stam et al Spectrum A=0 ocean Polarization cloud vegetation A=1

14 Spectroscopy Polarimetry Variability - Spectral time variation => variation of temperature Cloud free Earth from 0.65 to 0.9 µm 0.75 µm => surface properties - Polarimetric time variation => surface properties µm 50 Phase angle

15 How many detections?

16 How many detections? 1e-9 1e-10

17 How many detections? contrast Requirements : Small inner working angles 1e-9 1e-10

18 SEE-COAST proposed to ESA Cosmic Vision Parameter Value Hyperbolic secondary mirror 4,85m long Entrance pupil diameter D > 1.5m Angular resolution µm Contrast (after speckle 2 λ /D < 10-9 Contrast (after speckle 4 λ /D < Orbit for 6 months visibility, L2 Lagrangian high thermal stability Two folding mirrors Parabolic primary mirror Focal plane SEE-COAST UCF Orlando Submitted in 2007 to ESA Cosmic Vision 18

19 SEE-COAST : optical concept 1) Coronagraphy 2) Wavefront control (a few nm rms from science image) 3) Polarization+Spectral Differential imaging 1) visible light channel ( µm): 2 polarimetric arms 2) Near-IR channel ( µm): no polarimetry

20 Main component I: Achromatic Coronagraph Laboratory "planet" Contrast : Δλ/λ= 20% Visible light at 4.5λ/D Multi-stage four quadrant phase mask coronagraph Baudoz et al. 2007, 08

21 Main component II: Wavefront correction 2 stages WFS: 1st stage : Classical WFS+DM (~1 nm rms residuals) 2nd stage : Phase correction in coronagraphic image : wavefront error reduced by 100, spurious speckles by a factor (speckles nulling). 2 DMs concept is preferred (and envisioned) Speckle nulling in a limited FOV with a DM (JPL, Trauger & Traub, 07)

22 Main component III : Integral Field Spectrometer (R=40-80) Wavelength Field position

23 Main component IV : Reject efficiently spurious star speckles 1) differential polarimetry 2) spectral deconvolution (aberrations scale with λ)) 3) Self-coherent method (Baudoz, 07) Field position Wavelength Wavelength

24 Summary SEE COAST requires : High contrast : AND small IWA : 2 λ/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 (α 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)