POSTER ABSTRACTSP0303. POSTER SESSION IA new analysis of WASP-3bPOSTER CONTRIBUTIONSeptember 30, 2011M. Montalto 1 , J. Gregorio 3 , G. Boué 1 , M. Oshagh 1 , M. Maturi 4 , N. C. Santos 1,21. Centro de Astrofísica da Universidade do Porto (CAUP), Rua das Estrelas, 4150-762Porto, Portugal NIF 502 216 4502. Departemento de Fisica e Astronomía, Faculadade de Ciemcias, Universidade do Porto,Portugal3. Grupo Atalaia4. Zentrum fuer Astronomie, ITA, Universitaet Heidelberg, Albert-Ueberle-Str. 2, D-69120,Heidelberg, GermanyAbstractA battery of new transits of WASP-3b has been observed by our group. In this poster we presentour re-analysis of the properties of this planet. In particular we studied the entire sample oftransit timing and radial velocity measurements acquired so far, constraining the presence ofother perturbing planets in the system.11582011 <strong>Kepler</strong> Science Conference - <strong>NASA</strong> Ames Research Center
POSTER ABSTRACTSP0304. POSTER SESSION ITHE TASTE PROJECT: A GROUND-BASED SEARCH FOR TRANSIT TIME VARIATIONSV. Nascimbeni 1 , G. Piotto 2 , L. R. Bedin 3 , M. Damasso 4 , L. Malavolta 5 , L. Borsato 6 , and A. Cunial1Dipartimento di Astronomia, Università di Padova (UniPD), Vicolo dell'Osservatorio 3, 35122 Padova, Italy,valerio.nascimbeni@unipd.it, 2 UniPD, giampaolo.piotto@unipd.it, 3 INAF-OaPD, luigi.bedin@oapd.inaf.it,4UniPD, mario.damasso@unipd.it, 5 UniPD, luca.malavolta@studenti.unipd.it, 6 UniPD, luca.borsato.2@unipd.itIntroduction: Photometric transits represent agreat opportunity to discover and characterize extrasolarplanets. They are, for instance, the only directmethod to estimate the planetary radius and to constrainother important physical and orbital parameters.A new powerful technique is emerging in this field,able to detect low-mass companions in systems whereat least one planet is transiting. In principle, a singleplanet orbiting the host star in a <strong>Kepler</strong>ian orbit is expectedto transit at strictly periodic time intervals, unlessit is perturbed by a third body [1]. By performingaccurate measurements of the central instant time of aknown transiting planet, it is possible to detect deviationsfrom a linear ephemeris, and to infer the parametersof the perturber [2]. Such a search for other bodiesvia transit time variations (TTV) is very sensitiveto low-mass planets when they are locked in loworderorbital resonances. In these orbits, even earthmassperturbers would cause TTVs of the order of afew minutes, i.e. easily detectable with ground-basedtechniques.In the past few years, some authors have claimedTTV detections using ground-based facilities, for instancefrom WASP-3b [3] and HAT-P-13b [4], thoughnone have been independently confirmed so far. Incontrast, the <strong>Kepler</strong> mission found astonishing mutualTTVs for many systems, including five among sixplanets transiting on <strong>Kepler</strong>-11 [5]. These works havelead to the validation of those planets, as well as adeep characterization of their systems.The TASTE project. Our group started in 2010the TASTE project, previously known as The AsiagoSearch for Transit Timing Variations of Exoplanets[6]. Our goal is to perform an accurate photometricfollow-up of a small sample of transiting exoplanets,purposely chosen as suitable targets for a TTV search.We developed an independent pipeline for the data reduction(STARSKY, [6]). STARSKY is optimized tocarry out high-precision differential photometry overdefocused images. It implements empirical, iterativealgorithms to weight a set of reference stars, aiming atminimizing the final photometric scatter. Additionalroutines analyze the light curve itself to identify,model, and decorrelate any residual systematic error.A transit model is then fitted to the light curve by amodified version of JKTEBOP [7]. The uncertaintiesover each fitted parameter (including the central instantT 0) are estimated in the most conservative way,using both resampling and bootstrapping techniquessuch as the “residual-permutation” algorithm.TASTE observations started at the Asiago 1.82mtelescope in 2010, and are currently ongoing or scheduledat other medium-class facilities around theworld: IAC-80, TCS (Observatorio del Teide, CanaryIslands), NOT, TNG (ORM, Canary Islands), CTIO-0.9m (Cerro Tololo), REM (La Silla), and others.First results. On most targets, TASTE is able toachieve a photometric scatter of the order of 0.5mmag (120s bins) or better. The first light curves,published as test case (HAT-P-3b and HAT-P-14b,[6]) demonstrate a timing accuracy spanning ΔT 0=10-25 s on typical targets. Recently we published a TTVstudy that shed some light on the controversial case ofHAT-P-13b [7]. New results from the IAC facilitiesare going to be published.Fig. 1: Folded light curve of two TASTE transits ofWASP-3b observed at IAC-80 in 2011.References: [1] Holman & Murray (2005), Science,307, 1288 [2] Agol et al. (2005), MNRAS, 359,567 [3] Maciejewski et al. (2010), MNRAS, 411,1204 [4] Pal et al. (2011), MNRAS 413, L43 [5] Lissaueret al. (2010) Nature, 470, 53 [6] Nascimbeni etal. (2011a), A&A, 527, A85 [7] Southworth et al.(2004), MNRAS, 351, 1277 [8] Nascimbeni et al.(2011b), A&A 532, A24.2011 <strong>Kepler</strong> Science Conference - <strong>NASA</strong> Ames Research Center 159
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