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

By R. Alonso, M. Auvergne, A. Baglin, M. Ollivier, C. Moutou, D. Rouan, H. Deeg, Suzanne Aigrain, J. Almenara, M. Barbieri and 33 more. 2008

196 citations recorded by the source corpus.

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. The folded light curve of 78 transits is fitted to a model to obtain the main parameters. Radial velocity data obtained with the SOPHIE, CORALIE and HARPS spectrographs are combined to characterize the system. The 2.5 min binned phase-folded light curve is affected by the effect of sucessive occultations of stellar active regions by the planet, and the dispersion in the out of transit part reaches a level of 1.09 × 10 −4 in flux units. Results. We derive a radius for the planet of 1.465 ± 0.029 RJup and a mass of 3.31 ± 0.16 MJup, corresponding to a density of 1.31 ± 0.04 g/cm 3 . The large radius of CoRoT-Exo-2b cannot be explained by current models of evolution of irradiated planets.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/142ceb2c604af316c91a9033fb5861d1a5d44a1b

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Citations in the corpus

C/O RATIO AS A DIMENSION FOR CHARACTERIZING EXOPLANETARY ATMOSPHERES (2012, methodology): “In yet another case, no models have thus far been able to explain the dayside emission observed for the hot Jupiter CoRoT-2b (Deming et al. 2011).”
Stellar limb-darkening coefficients for CoRot and Kepler (2009, background): “A determination of the planet-tostar radius ratio is affected by stellar activity, as shown for CoRot-2 by Czesla et al. (2009) who re-determined the planetary radius, taking into account stellar activity, finding a larger radius than either Alonso et al. (2008) or Gillon et al. (2009).”
Stellar activity of planetary host star HD 189 733 (2008, background): “Planets around active stars are now found by research instruments such as CoRoT, and need radial-velocity follow-up (Alonso et al. 2008).”
HAT-P-16b: A 4 MJ PLANET TRANSITING A BRIGHT STAR ON AN ECCENTRIC ORBIT, (2010, background): “CoRoT-2b (Alonso et al. 2008) and CoRoT-6b (Fridlund et al. 2010) have similar masses and periods, but both have eccentricities consistent with zero.”
Transiting exoplanets from the CoRoT space mission . VI. CoRoT-Exo-3b: the first secure inhabitant of the brown-dwarf desert (2008, methodology): “The transit was analyzed using the same methodology as presented in Alonso et al. (2008), though the very low activity level of the star facilitates the analysis.”
HAT-P-11b: A SUPER-NEPTUNE PLANET TRANSITING A BRIGHT K STAR IN THE KEPLER FIELD (2009, background): “…transits are short events compared to the total orbital time, and have mostly been observed around stars with much smaller variation than the transit amplitude (note that there are exceptions; see Alonso et al. 2008), thus the underlying signal can be approximated with its median ∼95% of the time.”
TIDAL EVOLUTION OF CLOSE-IN PLANETS (2010, background): “Many groups have explored this possibility, motivated by observations of inflated radii for some transiting planets (e.g. Barge et al. 2008; Alonso et al. 2008; Johns-Krull et al. 2008; Gillon et al. 2009).”
PHOTOMETRIC VARIABILITY IN KEPLER TARGET STARS. II. AN OVERVIEW OF AMPLITUDE, PERIODICITY, AND ROTATION IN FIRST QUARTER DATA (2010, methodology): “An excellent longer span example of this is shown by CoRoT-Exo2b (Alonso et al. 2008).”
Magnetic activity in the photosphere of CoRoT-Exo-2a. Active longitudes and short-term spot cycle in (2008, methodology): “We adopt the same quadratic limb-darkening law of Alonso et al. (2008) with the parameters derived from the fitting of the planetary transit profile.”
CoRoT sounds the stars: p-mode parameters of Sun-like oscillations on HD 49933 (2008, background): “Since the launch of CoRoT, in 2006 December, the satellite has already detected several exoplanets (Barge et al. 2008; Alonso et al. 2008; Bouchy et al. 2008).”
Transiting exoplanets from the CoRoT space mission VIII. CoRoT-7b: the first Super-Earth with measured radius (2009, unknown): “Because the transi signal is proportional to the planet’s projected surface, th first publishedCoRoT results (Barge et al. 2008; Alonso et al. 2008; Deleuil et al. 2008; Aigrain et al. 2008; Moutou et al. 2008) were focused on the population of rather massive planets, one of which has even been…”
Homogeneous studies of transiting extrasolar planets – IV. Thirty systems with space-based light curves (2011, methodology): “CoRoT-2 A would benefit from an improvedTeff measurement: the discovery value of5625 ± 120K (Alonso et al. 2008) is comparatively uncertain, the alternative measurement of 5608± 37K by Ammler-von Eiff et al. (2009) accompanies alog g which is too high (4.71 versus 4.53), and the value of5696 ± 70K…”
EVIDENCE OF POSSIBLE SPIN–ORBIT MISALIGNMENT ALONG THE LINE OF SIGHT IN TRANSITING EXOPLANET SYSTEMS (2010, background): “Note that CoRoT-2 (Alonso et al. 2008) and HD 189733 (Bouchy et al. 2005) are known to be more active than the Sun, and therefore potential fast rotators.”