We report on the discovery of HAT-P-12b, a transiting extrasolar planet orbiting the moderately bright V~12.8 K4 dwarf GSC 03033-00706, with a period P=3.2130598+/-0.0000021d, transit epoch T_c_=2454419.19556+/-0.00020 (BJD), and transit duration 0.0974+/-0.0006d. The host star has a mass of 0.73+/-0.02M_{sun}_, radius of 0.70^+0.02^_-0.01_R_{sun}_, effective temperature 4650+/-60K, and metallicity [Fe/H]=-0.29+/-0.05. We find a slight correlation between the observed spectral line bisector spans and the radial velocity, so we consider, and rule out, various blend configurations including a blend with a background eclipsing binary, and hierarchical triple systems where the eclipsing body is a star or a planet. We conclude that a model consisting of a single star with a transiting planet best fits the observations, and show that a likely explanation for the apparent correlation is contamination from scattered moonlight. Based on this model, the planetary companion has a mass of 0.211+/-0.012M_J_ and radius of 0.959^+0.029^_-0.021_R_J_ yielding a mean density of 0.295+/-0.025g/cm^3^. Comparing these observations with recent theoretical models, we find that HAT-P-12b is consistent with a ~1-4.5Gyr, mildly irradiated, H/He-dominated planet with a core mass M_C_<~10M_{earth}_.
We report on the discovery of a planetary system with a close-in transiting hot Jupiter on a near circular orbit and a massive outer planet on a highly eccentric orbit. The inner planet, HAT-P-13b, transits the bright V=10.622 G4 dwarf star GSC 3416-00543 every P=2.916260+/-0.000010 days, with transit epoch T_c_=2454779.92979+/-0.00038 (BJD) and duration 0.1345+/-0.0017 days. The outer planet HAT-P-13c orbits the star every P_2_=428.5+/-3.0 days with a nominal transit center (assuming zero impact parameter) of T_2c_=2454870.4+/-1.8 (BJD) or time of periastron passage T_2,peri_=2454890.05+/-0.48 (BJD). Transits of the outer planet have not been observed, and may not be present. The host star has a mass of 1.22^+0.05^_-0.10_M_{sun}_, radius of 1.56+/-0.08R_{sun}_, effective temperature of 5653+/-90K, and is rather metal-rich with [Fe/H]=+0.41+/-0.08.
We report the discovery of HAT-P-17b,c, a multi-planet system with an inner transiting planet in a short-period, eccentric orbit and an outer planet in a 4.4 yr, nearly circular orbit. The inner planet, HAT-P-17b, transits the bright V=10.54 early K dwarf star GSC 2717-00417, with an orbital period P=10.338523+/-0.000009 days, orbital eccentricity e=0.342+/-0.006, transit epoch T_c_=2454801.16943+/-0.00020 (BJD: barycentric Julian dates throughout the paper are calculated from Coordinated Universal Time (UTC)), and transit duration 0.1690+/-0.0009 days. HAT-P-17b has a mass of 0.534+/-0.018M_J_ and radius of 1.010+/-0.029R_J_ yielding a mean density of 0.64+/-0.05g/cm3. This planet has a relatively low equilibrium temperature in the range 780-927K, making it an attractive target for follow-up spectroscopic studies. The outer planet, HAT-P-17c, has a significantly longer orbital period P_2_=1610+/-20d and a minimum mass m_2_sini_2_=1.31^+0.18^_-0.15_M_J_. The orbital inclination of HAT-P-17c is unknown as transits have not been observed and may not be present. The host star has a mass of 0.86+/-0.04M_{sun}_, radius of 0.84+/-0.02R_{sun}_, effective temperature 5246+/-80K, and metallicity [Fe/H]=0.00+/-0.08. HAT-P-17 is the second multi-planet system detected from ground-based transit surveys.
We observed with the SOPHIE spectrograph (OHP, France) the transit of the HAT-P-6b exoplanet across its host star. The resulting stellar radial velocities display the Rossiter-McLaughlin anomaly and reveal a retrograde orbit: the planetary orbital spin and the stellar rotational spin point towards approximately opposite directions.
We report the discovery of HATS-13b and HATS-14b, two hot-Jupiter transiting planets discovered by the HATSouth survey. The host stars are quite similar to each other (HATS-13: V=13.9 mag, M*=0.96M_{sun}_, R*=0.89R_{sun}_, Teff=5500K, [Fe/H]=0.05; HATS-14: V=13.8mag, M*=0.97M_{sun}_, R*=0.93R_{sun}_, Teff=5350K, [Fe/H]=0.33) and both the planets orbit around them with a period of roughly 3 days and a separation of roughly 0.04 au. However, even though they are irradiated in a similar way, the physical characteristics of the two planets are very different. HATS-13b, with a mass of Mp=0.543M_Jup_ and a radius of Rp=1.212R_Jup_, appears as an inflated planet, while HATS-14b, having a mass of Mp=1.071M_Jup_ and a radius of Rp=1.039R_Jup_, is only slightly larger in radius than Jupiter.
We present the first ground-based detection of thermal emission from an exoplanet in the H-band. Using HAWK-I on the VLT, we observed an occultation of WASP-19b by its G8V-type host star. WASP-19b is a Jupiter-mass planet with an orbital period of only 19 h, and thus, being highly irradiated, is expected to be hot. We measure an H-band occultation depth of (0.259^+0.046^_-0.044_)%, which corresponds to an H-band brightness temperature of T_H_=2580+/-125K. A cloud-free model of the planet's atmosphere, with no redistribution of energy from day-side to night-side, under predicts the planet/star flux density ratio by a factor of two. As the stellar parameters, and thus the level of planetary irradiation, are well-constrained by measurement, it is likely that our model of the planet's atmosphere is too simple.
We found evidence for a sub-stellar companion around the K giant star HD 110014. This cool evolved star, with a spectral type K2III and an estimated mass between 1.9 and 2.4M_{sun}-, is slightly metal rich with [Fe/H]=0.19 and a rotational velocity Vsini=2.0km/s. ************************************************************************** * * * Sorry, but the author(s) never supplied the tabular material * * announced in the paper * * * **************************************************************************
We compare limb darkening laws derived from 3D hydrodynamical model atmospheres and 1D hydrostatic MARCS models for the host stars of two well-studied transiting exoplanet systems, the late-type dwarfs HD 209458 and HD 189733. The surface brightness distribution of the stellar disks is calculated for a wide spectral range using 3D LTE spectrum formation and opacity sampling. We test our theoretical predictions using least-squares fits of model light curves to wavelength-integrated primary eclipses that were observed with the Hubble Space Telescope (HST).
We report the detection of a double planetary system around HD140718 as well as the discovery of two long period and massive planets orbiting HD171238 and HD204313. Those discoveries were made with the CORALIE Echelle spectrograph mounted on the 1.2-m Euler Swiss telescope located at La Silla Observatory, Chile. The planetary system orbiting the nearby G9 dwarf HD147018 is composed of an eccentric inner planet (e=0.47) with twice the mass of Jupiter (2.1M_Jup_) and with an orbital period of 44.24-days. The outer planet is even more massive (6.6M_Jup_) with a slightly eccentric orbit (e=0.13) and a period of 1008-days. The planet orbiting HD171238 has a minimum mass of 2.6M_Jup_, a period of 1523-days and an eccentricity of 0.40. It orbits a G8 dwarfs at 2.5AU. The last planet, HD204313 b, is a 4.0 M_Jup_-planet with a period of 5.3-years and has a low eccentricity (e=0.13). It orbits a G5 dwarfs at 3.1AU. The three parent stars are metal rich, which further strengthened the case that massive planets tend to form around metal rich stars.
We report near-infrared spectroscopy of the gas giant planet HD 189733b in transit. We used the Hubble Space Telescope Wide Field Camera 3 (HST WFC3) with its G141 grism covering 1.1 {mu}m to 1.7 {mu}m and spatially scanned the image across the detector at 2''/s. When smoothed to 75 nm bins, the local maxima of the transit depths in the 1.15 {mu}m and 1.4 {mu}m water vapor features are, respectively, 83+/-53 ppm and 200+/-47 ppm greater than the local minimum at 1.3 {mu}m. We compare the WFC3 spectrum with the composite transit spectrum of HD 189733b assembled by Pont et al., extending from 0.3 {mu}m to 24 {mu}m. Although the water vapor features in the WFC3 spectrum are compatible with the model of non-absorbing, Rayleigh-scattering dust in the planetary atmosphere, we also re-interpret the available data with a clear planetary atmosphere. In the latter interpretation, the slope of increasing transit depth with shorter wavelengths from the near infrared, through the visible, and into the ultraviolet is caused by unocculted star spots, with a smaller contribution of Rayleigh scattering by molecular hydrogen in the planet's atmosphere. At relevant pressures along the terminator, our model planetary atmosphere's temperature is ~700 K, which is below the condensation temperatures of sodium- and potassium-bearing molecules, causing the broad wings of the spectral lines of Na I and K I at 0.589 {mu}m and 0.769 {mu}m to be weak.