Survey
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Planetary Characterization Giovanna Tinetti University College London - France Allard (CRAL, radiative transfer, spectral models) - Nicole Allard (GEPI, spectroscopy of atomic species) - Alan Aylward et al. (UCL, 3D upper atm. modeling) - Bruno Bezard (LESIA, solar system, models/observations) - James Cho (QMUL, atmosphere dynamics) - Athena Coustenis (LESIA, solar system, models/obs.) - Olivier Grasset (Un. Nantes, planetary interior) - John Harries (Imperial College, Earth mod/obs) - Hugh Jones (Un. of Herthfordshire, exoplanet obs.) - Helmut Lammer (IWF/OeAW, upper atm.) - Emmanuel Lellouch (LESIA, solar system, model/obs.) - Enric Palle (IAC, Earth observations/biosig.) - Heike Rauer et al. (DLR, atmos/biosig. modeling) - Jean Schneider (LUTH, exoplanet observations) - Franck Selsis (Un. Bordeaux, planetary models/biosig.) - Daphne Stam (SRON, exoplanet polarization) - Jonathan Tennyson (UCL, spectroscopy of molecules) - Giovanna Tinetti (UCL, exoplanet spectral simulations) - Yuk Yung (Caltech, photochemistry/rad. transfer) Projects Spectral Bands Output Type of Planets High Accuracy RV Visible/N IR Mass, address, statistics Giant and super-Earths Cold Spitzer MIR Photometry and low res. spectroscopy of transiting planets Nearby Ho t Jupiters and Neptune s, Super-Earths around M stars? Warm Spitzer MIR Photometry at 3.6 and 4.5 micron Nearby Ho t Jupiters and Neptune s, Super-Earths around M stars? HS T (UV ) VIS, NIR Low, Mediu m, (High ) res. Spectroscopy for transiting planets Nearby Ho t Jupiters and Neptune s, Super-Earths around M-stars? SPHER E/GPI (2011) NIR Photometry & spectra Young/massiv e nearby giants VIS Photometry , polarization Young/massiv e nearby giants NIR-MIR Photometry & Down to Super-Earths & favourable Earth-size Planets; Habitabl e zone M-stars JWST (2013) High Res. Spectroscopy transiting planets SPICA (2018) (NIR)-MIRFIR Low & High Res. Spectroscopy transiting planets Down to Super-Earths & favourable Earth-size Planets; Habitabl e zone M-stars ELTs (2018-2020) VIS-NIR Spectroscopy, Photometry, Polarizatio n Matur e giants, super-Earths Small/ medium tele scope + Coronograph VIS + (NIR) (SEE-Coast, SPICAcoronograph , Epic, Peco, Access etc.) MIR Photometry & spectra & degree of polari zation Matur e giants, nearby superEarths Photometry & Spectra Astrometry / RV with ELT Visible Mass, address, statistics Earth sized pla nets, habitable zone TPF-C VIS (NIR) Low-Medi um Res. Spectroscopy ~ 100 Down to Earth sized planets in habitable zone TPF-O VIS (NIR) Mediu m Res. Spectroscopy 300-1000 Down to Earth sized planets in habitable zone TPF-I/Darwin MIR Low-Res. Spectroscopy < 40 Down to Earth sized planets in habitable zone Atmospheric characterisation: priorities for future missions • • • • • • • • Spectroscopy! Spectral resolution Signal to noise reachable Integration time Wavelength range Instrument sensitivity Redundancies to address degeneracy Variety of planetary types (Gas-giants, Neptunes, Terrestrial Planets, orbiting different types of stars, @ different orbital separation • Type of targets reachable dnv kav 2008 Contribution: advanced. Low res; spectroscopy from space. Higher res. from ground? Hot planets orbiting very close in, Targets down to Super-Earth UV-IR ~2015-2018 JWST, SPICA: High spectral res. from space, down to ~Earth-size, planets orbiting close-in, Habitable zone M-stars? IR Further into the future: Improved resolution, sensitivity, broader spectral window etc. 2008 Contribution: study phase. 2010: VLT-Sphere first light (warm Jupiters, large separation) ~2015-2018 Small size space-based missions? E-ELT-EPICS (ground) Low spectral res. ~ 65, planets with larger separation, down to Super-Earth size, Habitable zone VIS-NIR-MIR Further into the future: Large space-based missions, Planets down to Earth-size, Habitable zone Higher spect. resolution Transiting planets The present (Hubble, Spitzer, ground) Planets orbiting VERY close in + Photometry/low spectral resolution from space, very high spect. res from ground? Hot Jupiters, hot Neptunes, hot-Super Earths? Radial velocity / Occultation HD 209458b Period = 3.524738 days Mass = 0.69 ±0.05 MJupiter Radius = 1.35 ±0.04 RJupiter Density = 0.35 ±0.05 g/cm3 Radius/mass ratio Ice Silicate Carbon Sotin, Grasset & Mocquet; Kuchner & Seager; First atmospheric component: Na 0.0232±0.0057% Charbonneau et al., 2002 Sensitive to overall temperature, main atmospheric component, planetary mass Light curves of a non-transtiting exoplanet υ Andromeda light-curve @ 24 μm contribution from the planet: ~0.1% Harrington et al., Science, 2006 VIS-MIR transit spectroscopy Knutson et al., 2008 Pont et al., 2007 Deming et al., 2007 Charbonneau et al., 2008 Beaulieu et al., 2008 Swain et al., 2008 Knutson et al., 2008 QuickTime™ and a decompressor are needed to see this picture. Swain et al., 2008a Swain et al., 2008a + Grillmair, 2007 Swain, Vasisht, Tinetti, Bouwman, Deming, Nature, submitted H2O, CH4, CO + other C-N bearing molecules The short term future (JWST, SPICA?) Planets orbiting VERY close in + High spectral resolution from space Hot Jupiters, hot Neptunes, hot-Super Earths, hot Earth-size? Warm Earth-size (Mstar) James Webb Space Telescope performances (MIRI) Earth-size Planets @ 10, 20, 30 parsec Cavarroc, Cornia, Tinetti, Boccaletti, 2008 SPICA • Japanese (ISAS/JAXA) proposal for successor mission to Spitzer, Akari and Herschel • Telescope: 3.5m, <5 K – Herschel: 3.5m, 80K – JWST: ~6m, ~45K • Core λ: 5-200 μm – Δθ=0.35”-14” • Orbit: Sun-Earth L2 Halo • Warm Launch, Cooling in Orbit – No Cryogen → 3.2 t – Long Lifetime • Launch: 2017 Primary and secondary transit photometry/spectroscpy have been shown to be very powerful diagnostic techniques to probe the atmospheres of extrasolar planets. But for planets with larger separation from the Star… Direct detection Stellar light reflected by the planet (UV/visible) g Molecules/clouds/surface types Multiple scattering of reflected photons: Rayleigh scattering/clouds/surface types Molecules with electronic transitions Photons emitted by the planet (IR) Molecules/thermal structure g Photons emitted by the planet, Molecules (roto-vibrational modes), thermal structure, clouds O3 In the visible, sunlight is reflected and scattered back to the observer, and is absorbed by materials on the planet’s surface and in its atmosphere. Net 60 Stratopause 50 The planet is warm and gives off its own infrared radiation. As this radiation escapes to space, materials in the atmosphere absorb it and produce spectral features. Emission 40 Ozone Absorption 30 20 Tropopause 10 Absorption Water Vapor 0 200 250 300 VIS - Near IR Molecules in 0.4-2.5 microns Molecule Absorption bands (μm) H2O 0.51, 0.57, 0.61, 0.65, 0.72, 0.82, 0.94, 1.13, 1.41, 1.88, 2.6 CH4 0.48, 0.54, 0.57. 0.6, 0.67, 0.7, 0.79, 0.84, 0.86, 0.73, 0.89, 1.69, 2.3 CO2 1.21, 1.57, 1.6. 2.03 NH3 0.55, 0.65, 0.93, 1.5, 2, 2.3 O3 0.45-0.75 (the Chappuis band) O2 0.58, 0.69, 0.76, 1.27 CO 1.2, 1.7, 2.4 H 2S VIS: Albedo H2O, CH4, NH3, C2H6, CO, H2S, CO2 … Karkoschka, Icarus, 1998 Terrestrial Planet Spectra Vary Widely in Solar System VIS-Near-IR signatures for terrestrial planets in our Solar System ? CO2 CO2 VENUS X 0.60 EARTH-CIRRUS O2 O3 H2O H2O H2O O2 H2O MARS Iron oxides H2O ice EARTH-OCEAN Polarization: a huge help to distinguish clouds Polarization variations 10%-40% (Stam et al 2004) => Starlight is NOT polarized Polarization: sensitivity to phase Polarization variations 10%-40% (Stam et al 2004) => Starlight is NOT polarized IR Molecules in the Mid-IR H2O, CO2, CH4, Hydrocarbons, HCN, H2S, SO2, CO, N2O, NH3 …. QuickTime™ and a decompressor are needed to see this picture. QuickTime™ and a decompressor are needed to see this picture. QuickTime™ and a decompressor are needed to see this picture. Terrestrial Planet Spectra Widely in Solar System MIR signatures forVary terrestrial planets in our Solar System IR: Thermal structure, dynamics Knutson et al., Nature, 2007; ApJ, 2008 ESO Extremely Large Telescope-EPICS EPICS is an instrument project for the direct imaging and characterization of extra-solar planets with the European ELT • The eXtremeAdaptive Optics(XAO) system - The Diffraction Suppression System(or coronagraph) - The Speckle Suppression System • The Scientific Instrument(s) - Integral Field Spectroscopy - Differential Polarimetry - A speckle coherence-based instrument QuickTime™ and a decompressor are needed to see this picture. Missions concepts considered for studies (US) Access: coronagraphs for exoplanet missions (John Trauger) Davinci, Dilute Aperture VIsible Nulling Coron. Imager(Michael Shao) EPIC: directly imaging exoplanets orbiting nearby stars (Mark Clampin) PECO: refining a Phase Induced Amplitude Apodization Coronograph (Olivier Guyon) QuickTime™ and a decompressor are needed to see this picture. M-mission from space or first generation from ground QuickTime™ and a decompressor are needed to see this picture. QuickTime™ and a decompressor are needed to see this picture. The New World Observer NWO is a large-class Exoplanet mission that employs two spacecrafts: a “starshade” to suppress starlight before it enters the telescope and a conventional telescope to detect and characterize exo-planets. Cash, Nature, 2006 Spectroscopy QuickTime™ and a decompressor are needed to see this picture. H2O O2 CH4 NH3 S. Seager Coronagraph on SPICA • Assumed observation mode - imaging and low res. spectroscopy - because of limit of sensitivity • Distance/number of target - a few hundred of target in 10pc - a few x 10 seems too small - a few x 1000 is difficult to complete survey • Wavelength - 3.5-27um rather than 5-27um to detect excess in spectral, and advantage on IWA. • IWA - limited by coronagraph method. - 3.3 lambda/D (binary mask mode, baseline of SPICA coronagrah) - 1.2-1.5 lambda/D (PIAA mode) • Contrast - finally 10^-7. To obtain it, 10^-6 for raw contrast. (~10 is assumed as gain of subtraction) Enya et al., 2008 Direct Detection of Earth-size Planets IR