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dc.contributor.authorMaire, Anne-Lise
dc.contributor.authorGalicher, Raphael
dc.contributor.authorBoccaletti, Anthony
dc.contributor.authorBaudoz, Pierre
dc.contributor.authorSchneider, J.
dc.contributor.authorCahoy, Kerri
dc.contributor.authorStam, D. M.
dc.contributor.authorTraub, W. A.
dc.date.accessioned2013-09-17T16:16:30Z
dc.date.available2013-09-17T16:16:30Z
dc.date.issued2012-05
dc.date.submitted2012-02
dc.identifier.issn0004-6361
dc.identifier.issn1432-0746
dc.identifier.urihttp://hdl.handle.net/1721.1/80774
dc.description.abstractContext: High-contrast imaging is currently the only available technique for the study of the thermodynamical and compositional properties of exoplanets in long-period orbits, comparable to the range from Venus to Jupiter. The SPICES (Spectro-Polarimetric Imaging and Characterization of Exoplanetary Systems) project is a coronagraphic space telescope dedicated to the spectro-polarimetric analysis of gaseous and icy giant planets as well as super-Earths at visible wavelengths. So far, studies for high-contrast imaging instruments have mainly focused on technical feasibility because of the challenging planet/star flux ratio of 10-8−10-10 required at short separations (200 mas or so) to image cold exoplanets. However, the main interest of such instruments, namely the analysis of planet atmospheric/surface properties, has remained largely unexplored. Aims: The aim of this paper is to determine which planetary properties SPICES or an equivalent direct imaging mission can measure, considering realistic reflected planet spectra and instrument limitation. Methods: We use numerical simulations of the SPICES instrument concept and theoretical planet spectra to carry out this performance study. We also define a criterion on the signal-to-noise ratio of the measured spectrum to determine under which conditions SPICES can retrieve planetary physical properties. Results: We find that the characterization of the main planetary properties (identification of molecules, effect of metallicity, presence of clouds and type of surfaces) would require a median signal-to-noise ratio of at least 30. In the case of a solar-type star ≤10 pc, SPICES will be able to study Jupiters and Neptunes up to ~5 and ~2 AU respectively, because of the drastic flux decrease with separation. It would also analyze cloud and surface coverage of super-Earths of radius 2.5 Earth radii at 1 AU. Finally, we determine the potential targets in terms of planet separation, radius and distance for several stellar types. For a Sun analog, we show that SPICES could characterize Jupiters (M ≥ 30 Earth masses) as small as 0.5 Jupiter radii at ≲2 AU up to 10 pc, and super-Earths at 1−2 AU for the handful of stars that exist within 4−5 pc. Potentially, SPICES could perform analysis of a hypothetical Earth-size planet around α Cen A and B. However, these results depend on the planetary spectra we use, which are derived for a few planet parameters assuming a solar-type host star. Grids of model spectra are needed for a further performance analysis. Our results obtained for SPICES are also applicable to other small (1−2 m) coronagraphic space telescopes.en_US
dc.description.sponsorshipFrance. Ministère de l'éducation nationale (Doctoral fellowship)en_US
dc.language.isoen_US
dc.publisherEDP Sciencesen_US
dc.relation.isversionofhttp://dx.doi.org/10.1051/0004-6361/201218954en_US
dc.rightsArticle is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.en_US
dc.sourceEDP Sciencesen_US
dc.titleAtmospheric characterization of cold exoplanets using a 1.5-m coronagraphic space telescopeen_US
dc.typeArticleen_US
dc.identifier.citationMaire, A.-L., R. Galicher, A. Boccaletti, P. Baudoz, J. Schneider, K. L. Cahoy, D. M. Stam, and W. A. Traub. “Atmospheric characterization of cold exoplanets using a 1.5-m coronagraphic space telescope.” Astronomy & Astrophysics 541 (May 3, 2012): A83.en_US
dc.contributor.departmentMassachusetts Institute of Technology. Department of Aeronautics and Astronauticsen_US
dc.contributor.mitauthorCahoy, Kerrien_US
dc.relation.journalAstronomy & Astrophysicsen_US
dc.eprint.versionFinal published versionen_US
dc.type.urihttp://purl.org/eprint/type/JournalArticleen_US
eprint.statushttp://purl.org/eprint/status/PeerRevieweden_US
dspace.orderedauthorsMaire, A.-L.; Galicher, R.; Boccaletti, A.; Baudoz, P.; Schneider, J.; Cahoy, K. L.; Stam, D. M.; Traub, W. A.en_US
dc.identifier.orcidhttps://orcid.org/0000-0002-7791-5124
mit.licensePUBLISHER_POLICYen_US


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