===================================================================== TALKS @ S4 Author: Roi Alonso & the CoRoT Exoplanet Science Team Title: The CoRoT mission Abstract: Launched in December 2006, the 27-cm aperture CoRoT (Convection, Rotation and Transits) mission has pioneered the search for exoplanets from space. Led by the french space agency CNES, with participation of several european countries and Brazil, it surveys up to 12000 stars per observing run, which last from 30 days to 150 days. The talk will summarize the main achievements of CoRoT, which include the discovery of the first transiting objects with masses in the brown dwarf regime (CoRoT-3b, CoRoT-15b), of the first transiting Super-Earth planet (CoRoT-7b), and of the temperate transiting Jupiter CoRoT-9b. After having observed more than 100000 stars, the transit detection capabilities and main limitations of CoRoT (whose extended mission period has been approved until March 2013) will be discussed. =========================================================================== Authors: Batalha, N.M., Borucki, W. J., Koch, D.G., and The Kepler Team Title: Micro and Macro Transits in the Publicly Released Kepler Data Abstract: In June, 2010, NASA's Kepler mission released photometric light curves taken at a 30-minute cadence over two epochs: 1) 9.7 days at the end of the commissioning period in May 2009 (52,664 stars brighter than m=13.6 in the Kepler bandpass) and 2) 33.5 days between commissioning and the first quarterly roll of the spacecraft in June 2009 (~156,000 stars brighter than m=16). Over three hundred transiting exoplanet candidates were identified in the released data as well as over 1,800 eclipsing binary stars. Herein, we describe the vetting and characterization procedures used to produce the exoplanet and eclipsing binary catalogues that were released to the public. We discuss the statistical properties of the populations and highlight particularly interesting and/or rare types of systems. Finally, we summarize the work leading up to the next data release which will occur in February 2011. =============================================================== Title: The WFCAM Transit Survey: a search for rocky planets around cool stars Authors: J.L Birkby, S. Hodgkin, D. Pinfield, the WTS consortium & the RoPACS consortium Abstract: The theory of core accretion makes two intriguing, observable predictions: i) that the formation of rocky/icy planets is common around M-dwarfs, and ii) that hot-Jupiters are extremely difficult to produce around low-mass stars. Furthermore, due to their small physical size and lower bolometric luminosity, M-dwarfs are up to 300 x more sensitive to planetary transits in their habitable zones than solar-type stars. We present here the WFCAM Transit Survey (WTS); an ambitious, near-infrared photometric monitoring campaign of ~6000 M-dwarfs across four 1.5 sq deg fields situated >5 degrees above and below the galactic plane. We utilise a unique opportunity provided by the highly efficient queue-scheduled operational mode of the UKIRT to observe our fields, with at least one visible at any time, when atmospheric conditions and RA coverage are unsuitable for other ongoing UKIRT programs. By probing the peak of the M-dwarf spectral energy distribution (13<17), we obtain a statistically significant sample of low-mass stars, which allows us to place meaningful constraints on the occurrence and formation of planets around M-dwarfs. The WTS has achieved one thousand epochs after 2 years in one of our target fields and will continue until April 2012. Our light curves have a per datapoint photometric precision of ~3-4 mmag for the brightest objects, with RMS scatter < 1% for J< 16, sufficient to detect Earth-like transits around M-dwarfs. I report here on the goals of our survey, our most recent results and the properties of our M-dwarf target sample. I also discuss our processing methods and how we combat the challenges encountered when observing occultations of faint red stars and the spectroscopic follow-up required to confirm them. (http://www.ast.cam.ac.uk/~sth/wts/index.html) ================================================================== Authors: Antonio Claret, Alvaro Giménez Title: Limb-darkening effects in planetary transits Abstract: The importance of a good treatment of limb-darkening effects in the analysis of light curves is well known but it is shown to be even more relevant in the case of exoplanetary transits than in eclipsing binary stars. The numerical methods used to compute limb-darkening coefficients are nevertheless still a matter of discussion. To improve the situation, we have revised our earlier calculations and compare the new coefficients with previous theoretical values, as well as with empirical measurements from nine eclipsing binaries. Such a comparison reveals that the theoretical atmosphere models are unable to give a satisfactory fit to the observations. This unexpected result is further supported by a recent investigation of transiting extrasolar planets as it is the case of the prototypical HD 209458. ===================================================================================== Title: Searching for exoplanets from time-series observations Authors: Carlos del Burgo Abstract: We apply a time-series analysis to public space- and ground-based observations in order to detect extrasolar planets. The methodology used is based on various techniques of signal processing. We mimic the data by means of a sinusoidal function. The Lomb-Scargle periodogram provides the spectrum of fundamental frequencies. Then, it is introduced a certain number of harmonic frequencies. A least squares fitting is applied to determine the amplitudes and phases of the function. The impact of cosmic rays, instrumental noise, scintillation noise and stray-light, among others effects, is studied. ========================================================================= Author: Alvaro Giménez Title: From eclipsing binaries to planetary transits Abstract: The analysis of the light curves of eclipsing binaries has proven to be a powerful tool in the determination of accurate stellar dimensions across the HR diagram. When the first extrasolar transiting planet was discovered some ten years ago it was immediately understood that a key observational source of information for their characterization had been open. In this presentation, some of the lessons learnt in the study of eclipsing binaries that are useful for the understanding of exoplanets are discussed. This includes the mathematical characterization of transits, the equations for the computation of the Rossiter effect in the radial velocity curves, and several analytical expressions allowing a precise estimation of the elements previous to a full analysis of the observed light curves. ====================================================================================== Title: Polarization effects in the transiting planetary system HD 189733 Authors: Nadia M. Kostogryz, T.M.Yakobchuk, A.P.Vidmachenko, O.V.Morozhenko Abstract: We present the results of the calculations of polarization effects in the transiting planetary system HD 189733 using the method proposed by Carciofi & Magalhães (2005) [1]. It suggests that the stellar radiation coming from different parts of the disk is polarized to various extent with maximum observed on the limb. Obviously, the total radiation from a single star is unpolarized due to the spherical symmetry, while the transiting planet breaks this symmetry of the stellar disk and the additional polarization effects appear in the system. There are 80 transiting planetary systems discovered to date. HD 189733 is one of the most studied such systems with a short-period (2.2d) Jupiter-like planet transiting the disc of the star. The distance from the host star to hot-Jupiter is only 0.031 AU, and the radii ratio is near Rplanet/Rstar = 0.15. Accounting for this together with other parameters, we consider HD 189733 as one the most useful objects to study polarization effects in the future observations. The linear polarization in the planetary system HD 189733 was found from 3D Monte-Carlo modeling using the non-linear stellar limb darkening law from Claret (2000) [2]. In our calculations we adopted the linearly polarized solar limb spectrum from Bueno & Shchukina (2009)[3]. Our preliminary results show that polarization degree in the systems like HD 189733 can be up to 0.07%. ================================================================= Title: Magnetic activity of CoRoT-6 and CoRoT-7 Authors: A. F. Lanza, A. S. Bonomo, I. Pagano, G. Leto, S. Messina, G. Cutispoto, C. Moutou, S. Aigrain, R. Alonso, P. Barge, M. Deleuil, M. Fridlund, A. Silva-Valio, M. Auvergne, A. Baglin, and A. Collier Cameron Abstract: We model the photospheric activity of CoRoT-6a and CoRoT-7a, two stars hosting planets, and use the maps of the active regions to study stellar differential rotation, and spot evolution. We find convincing evidence for star-planet interaction in the CoRoT 6 system. We show that information derived from light curve modeling can be used for a better understanding of the impact of magnetic activity on stellar RV variations, specifically to quantitatively assess the probability a given signal detected in the RV curve is due to stellar activity. ================================================================================== Title: PLATO: a Cosmic Vision project to detect and characterize planetary systems Authors: Pagano I., Fridlund M., Catala C., and the PLATO Consortium Abstract: PLATO (PLAnetary Transits and Oscillations of stars) is one of the three medium (M) class missions selected by ESA, in the framework of its Cosmic Vision 2015-2025 program, to enter a definition study phase. The main scientific goals of PLATO are the i) discovery and study of extra-solar planetary systems, (including those hosting Earth- like planets in their habitable zone) by means of planetary transits detection from space and radial velocity follow-up from ground, and ii) the characterization of the hosting stars through seismic analysis, in order to determine with high accuracy planetary masses and ages. We present the PLATO science objectives, the design of the PLATO Payload, and its performances. ================================================================== Title: Observations and modelling of Earth's transmission spectrum trough lunar eclipses: a window to transiting exoplanet characterization Authors: Enric Palle, Antonio Garcia-Muñoz Abstract: Recently we were able to retrieve the Earth's transmission spectrum trough lunar eclipse observations. This spectrum showed that the depth of most molecular species was stronger than models had anticipated. The presence of other atmospheric signatures, such as atmospheric dimers and Earth ionospheric absorption were also present in the spectrum. Since 2008 we have been developing a radiative transfer code able to reproduce the Eart'?s transmission spectra at different depths in to the penumbra and umbra, and taking into account transmission, refraction, multiple scattering and diffuse light. Here we show the excellent fits of our simulations to the eclipse data at visible and near-infrared wavelength ranges. We will also discuss the results of new eclipse observations at different wavelength ranges and resolutions. ==================================================================