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Transiting exoplanets from the CoRoT space mission. V. CoRoT-Exo-4b: stellar and planetary parameters

REA Auditado

Aims. The CoRoT satellite has announced its fourth transiting planet (Aigrain et al. 2008, A&A, 488, L43) with space photometry. We describe and analyse complementary observations of this system performed to establish the planetary nature of the transiting body and to estimate the
fundamental parameters of the planet and its parent star.
Methods. We have analysed high precision radial-velocity data, ground-based photometry, and high signal-to-noise ratio spectroscopy.
Results. The parent star CoRoT-Exo-4 (2MASS 06484671-0040219) is a late F-type star of mass of 1.16 MΘ and radius of 1.17 RΘ.

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Transiting exoplanets from the CoRoT space mission. I. CoRoT-Exo-1b: a low-density short-period planet around a G0V star

REA Auditado

Context. The pioneer space mission for photometric planet searches, CoRoT, steadily monitors about 12 000 stars in each of its fields of view. Transit candidates can be detected early in the processing of the data and before the end of a run of observation.
Aims. We report the detection of the first planet discovered by CoRoT and characterizing it with the help of follow-up observations.
Methods. Raw data were filtered from outliers and residuals at the orbital period of the satellite.

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Transiting exoplanets from the CoRoT space mission. IV. CoRoT-Exo-4b: a transiting planet in a 9.2 day synchronous orbit

REA Auditado

CoRoT, the first space-based transit search, provides ultra-high-precision light curves with continuous time-sampling over periods of up to 5 months. This allows the detection of transiting planets with relatively long periods, and the simultaneous study of the host star’s photometric variability. In this Letter, we report the discovery of the transiting giant planet CoRoT-Exo-4b and use the CoRoT light curve to perform a detailed analysis of the transit and determine the stellar rotation period.

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Transiting exoplanets from the CoRoT space mission. VII. The “hot-Jupiter”-type planet CoRoT-5b

REA Auditado

Aims. The CoRoT space mission continues to photometrically monitor about 12,000 stars in its field-of-view for a series of target fields to search for transiting extrasolar planets ever since 2007. Deep transit signals can be detected quickly in the “alarm-mode” in parallel to the ongoing target field monitoring. CoRoT’s first planets have been detected in this mode.
Methods. The CoRoT raw lightcurves are filtered for orbital residuals, outliers, and low-frequency stellar signals. The phase folded lightcurve is used to fit the transit signal and derive the main planetary parameters.

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Transiting exoplanets from the CoRoT space mission. II. CoRoT-Exo-2b: a transiting planet around an active G star

REA Auditado

Context. The CoRoT mission, a pioneer in exoplanet searches from space, has completed its first 150 days of continuous observations of ~12 000 stars in the galactic plane. An analysis of the raw data identifies the most promising candidates and triggers the ground-based follow-up.
Aims. We report on the discovery of the transiting planet CoRoT-Exo-2b, with a period of 1.743 days, and characterize its main parameters.
Methods. We filter the CoRoT raw light curve of cosmic impacts, orbital residuals, and low frequency signals from the star.

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Transiting exoplanets from the CoRoT space mission. VI. CoRoT-Exo-3b: the first secure inhabitant of the brown-dwarf desert

REA Auditado

Context. The CoRoT space mission routinely provides high-precision photometric measurements of thousands of stars that have been continuously observed for months.
Aims. The discovery and characterization of the first very massive transiting planetary companion with a short orbital period is reported.
Methods. A series of 34 transits was detected in the CoRoT light curve of an F3V star, observed fromMay to October 2007 for 152 days.

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Transiting exoplanets from the CoRoT space mission. VIII. CoRoT-7b: the first super-Earth with measured radius

REA Auditado

Aims. We report the discovery of very shallow (ΔF/F ≈ 3.4×10−4), periodic dips in the light curve of an active V = 11.7 G9V star observed by the CoRoT satellite, which we interpret as caused by a transiting companion. We describe the 3-colour CoRoT data and complementary ground-based observations that support the planetary nature of the companion.
Methods.

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Transiting exoplanets from the CoRoT space mission. III. The spectroscopic transit of CoRoT-Exo-2b with SOPHIE and HARPS

REA Auditado

We report on the spectroscopic transit of the massive hot-Jupiter CoRoT-Exo-2b observed with the high-precision spectrographs SOPHIE and HARPS. By modeling the radial velocity anomaly occurring during the transit due to the Rossiter-McLaughlin (RM) effect, we determine the sky-projected angle between the stellar spin and the planetary orbital axis to be close to zero λ = 7.2 ± 4.5 deg, and we secure the planetary nature of CoRoT-Exo-2b. We discuss the influence of the stellar activity on the RM modeling. Spectral analysis of the parent star from HARPS spectra are presented.

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Accuracy of stellar parameters of exoplanet-host stars determined from asteroseismology

REA Auditado

Context. In the context of the space-based mission CoRoT, devoted to asteroseismology and search for planet transits, we analyse the accuracy of fundamental stellar parameters (mass, radius, luminosity) that can be obtained from asteroseismological data.
Aims. Our work is motivated by the large uncertainties on planetary radius determination of transiting planets which are mainly due to uncertainties on the stellar parameters. Our goal is to analyse uncertainties of fundamental stellar parameters for a given accuracy of oscillation frequency determination.
Methods.

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Characterising stellar micro-variability for planetary transit searches

REA Auditado

A method for simulating light curves containing stellar micro-variability for a range of spectral types and ages is presented. It is based on parameter-by-parameter scaling of a multi-component fit to the solar irradiance power spectrum (based on VIRGO/PMO6 data), and scaling laws derived from ground based observations of various stellar samples.
A correlation is observed in the Sun between the amplitude of the power spectrum on long (weeks) timescales and the BBSO Ca II K-line index of chromospheric activity.

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