Presentation on theme: "A window to transiting exoplanet characterization."— Presentation transcript:
1 A window to transiting exoplanet characterization. Observations and modeling of Earth’s transmission spectrum through lunar eclipses:A window to transiting exoplanet characterization.E. Palle, M.R. Zapatero, P. Montañes-Rodriguez, R. Barrena, A. Garcia-Muñoz
24 Still, we must pursue the characterization with direct observations Exploration of surface featuresPresence of continentsRotational periodLocalized surface biomarkers (vegetation)Orbital light curveOcean glints and polarization effects
52 ConclusionsWe have obtained the Earths transmission spectra μmFirst order detection and characterization of the main constituents of the Earth's atmosphereDetection of the Ionosphere : Ca II, ( Mg, Fe, ??)Detection of O2•O2 and O2•N2 interactionsOffers more information than the reflectance spectraWe are developing models to understand the Earth’s transmission spectrum and extend this knowledge to extrasolar transiting rocky planetsUsing the measured Earth transmission spectrum and several stellar spectra, we compute the probability of characterizing a transiting earth with E-ELTFor a Earth in the habitability zone of an M-star, it is possible to detect H2O , O2 , CH4 ,CO2 (= Life) within a few tens of hours of observations.
54 How deep we see in the planet atmosphere? h min ?Are antropogenic signatures visible in the lower layers?Is there a surface signal?Traub, 2009
55 But, how far are we from making the measurements ? Thus, the transmission spectrum of telluric planets contains more information for the atmospheric characterization than the reflected spectrum.And it is also lesstechnically challengingBut, how far are wefrom making themeasurements ?
59 Molecular complexes in the Earth’s atmosphere: the dimers Van de Waals molecules: Weakly bound complexesThey are present as minor rather than trace species.One likely origin of continuum absorption.Observed on Earth (gas) and Jupiter (gas; (H2)2), Ganymede, Europa and Callisto (condensed), and in the laboratory (gas/condensed).Never on Venus/Mars, where there must be CO2 – XNOT contained in the common spectral librariesCalo and Narcisi (1980)Their total abundance is confined to the lower scale height of the atmosphere.
65 The Ring effect Rotational Raman Scattering (RRS) Early evidence:Sky-scattered Fraunhofer lines were less deep but broader than solar linesIncidentexitingλex-Δλ, λex, λex+Δλfrequency redistributionIncident λ + Stokes +Anti-Stokes branchesincident photonλexdifference/ratio
66 M8 star + 1 Earth ... with the E-ELT Wavelength (μm)Wavelength (μm)Work in progress ...
67 The Ring effect: Rotational Raman scattering Vountas et al. (1998)Transmission spectrumSolar spectrum
75 CoRoT & KEPLER can provide this input Many other surveys: Plato, TESS, Ground-based searches, ...Terrestrial inner-orbit planets based on their transits:- About planets if most have R ~ 1.0 Re- About 185 planets if most have R ~ 1.3 ReAbout 640 planets if most have R ~ 2.2 Re (Or possibly some combination of the above)About 12% of the cases with two or more planets per system