PlanetaryCharacterization 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)

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 different orbital separation Type of targets reachable

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~ 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)~ 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 dnv kav

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 Period = days Period = days Mass = 0.69 ±0.05 M Jupiter Radius = 1.35 ±0.04 R Jupiter Density = 0.35 ±0.05 g/cm 3 Density = 0.35 ±0.05 g/cm 3 HD b

Sotin, Grasset & Mocquet; Kuchner & Seager; Radius/mass ratio Ice Silicate Carbon

Charbonneau et al., ±0.0057%

Sensitive to overall temperature, main atmospheric component, planetary mass

Harrington et al., Science, 2006 υ Andromeda 24 μm contribution from the planet: ~0.1% Light curves of a non-transtiting exoplanet

VIS-MIR transit spectroscopy VIS-MIR transit spectroscopy Swain, Vasisht, Tinetti, Bouwman, Deming, Nature, submitted Swain et al., 2008a Swain et al., 2008a + Grillmair, 2007 Charbonneau et al., 2008 Knutson et al., 2008 Deming et al., 2007 Knutson et al., 2008 Beaulieu et al., 2008 Swain et al., 2008 Pont et al., 2007 d H 2 O, CH 4, 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)

Cavarroc, Cornia, Tinetti, Boccaletti, 2008 James Webb Space Telescope performances (MIRI) Earth-size 10, 20, 30 parsec

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 : μm –Δ θ =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)  Multiple scattering of reflected photons: Rayleigh scattering/clouds/surface types Molecules with electronic transitions Molecules/clouds/surface types  Photons emitted by the planet, Molecules (roto-vibrational modes), thermal structure, clouds Photons emitted by the planet (IR) Molecules/thermal structure

O3O Tropopause Stratopause Water Vapor Ozone Absorption Net Emission 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. 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.

VIS - Near IR

Molecules in microns MoleculeAbsorption bands (μm) H2OH2O0.51, 0.57, 0.61, 0.65, 0.72, 0.82, 0.94, 1.13, 1.41, 1.88, 2.6 CH , 0.54, , 0.67, 0.7, 0.79, 0.84, 0.86, 0.73, 0.89, 1.69, 2.3 CO , 1.57, NH , 0.65, 0.93, 1.5, 2, 2.3 O3O (the Chappuis band) O2O2 0.58, 0.69, 0.76, 1.27 CO1.2, 1.7, 2.4 H2SH2S

Karkoschka, Icarus, 1998 H 2 O, CH 4, NH 3, C 2 H 6, CO, H 2 S, CO 2 …

Terrestrial Planet Spectra Vary Widely in Solar System O2O2 Iron oxides CO 2 H2OH2OH2OH2O EARTH-CIRRUS VENUS X 0.60 MARS EARTH-OCEAN H2OH2O H2OH2O H 2 O ice ? O3O3 O2O2 VIS-Near-IR signatures for terrestrial planets in our Solar System

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

H 2 O, CO 2, CH 4, Hydrocarbons, HCN, H 2 S, SO 2, CO, N 2 O, NH 3 …. Molecules in the Mid-IR

Terrestrial Planet Spectra Vary Widely in Solar System MIR signatures for terrestrial planets in our Solar System

Knutson et al., Nature, 2007; ApJ, 2008 IR: Thermal structure, dynamics IR: Thermal structure, dynamics

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

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)

M-mission from space or first generation from ground

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 The New World Observer

Spectroscopy O2O2 H2OH2O CH 4 NH 3 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 um rather than 5-27um to detect excess in spectral, and advantage on IWA. IWA - limited by coronagraph method lambda/D (binary mask mode, baseline of SPICA coronagrah) lambda/D (PIAA mode) Contrast - finally 10^-7. To obtain it, 10^-6 for raw contrast. (~10 is assumed as gain of subtraction)

Direct Detection of Earth-size Planets IR