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Saint Jean, France

Moutou C.,French National Center for Scientific Research | Hebrard G.,University Pierre and Marie Curie | Hebrard G.,French National Center for Scientific Research | Bouchy F.,French National Center for Scientific Research | And 23 more authors.
Astronomy and Astrophysics | Year: 2014

We present high-precision radial-velocity measurements of three solar-type stars: HD 13908, HD 159243, and HIP 91258. The observations were made with the SOPHIE spectrograph at the 1.93 m telescope of the Observatoire de Haute-Provence (France). They show that these three bright stars host exoplanetary systems composed of at least two companions. HD 13908 b is a planet with a minimum mass of 0.865 ± 0.035MJup on a circular orbit with a period of 19.382 ± 0.006 days. There is an outer massive companion in the system with a period of 931 ± 17 days, e = 0.12 ± 0.02, and a minimum mass of 5.13 ± 0.25MJup. The star HD 159243 also has two detected companions with respective masses, periods, and eccentricities of Mp= 1.13 ± 0.05 and 1.9 ± 0.13MJup, P = 12.620 ± 0.004 and 248.4 ± 4.9 days, and e = 0.02 ± 0.02 and 0.075 ± 0.05. Finally, the star HIP 91258 has a planetary companion with a minimum mass of 1.068 ± 0.038MJup, an orbital period of 5.0505 ± 0.0015 days, and a quadratic trend indicating an outer planetary or stellar companion that is as yet uncharacterized. The planet-hosting stars HD 13908, HD 159243, and HIP 91258 are main-sequence stars of spectral types F8V, G0V, and G5V, respectively, with moderate activity levels. HIP 91258 is slightly over-metallic, while the other two stars have solar-like metallicity. The three systems are discussed in the frame of formation and dynamical evolution models of systems composed of several giant planets. © ESO, 2014.

Mousis O.,University of Franche Comte | Hueso R.,University of the Basque Country | Beaulieu J.-P.,French National Center for Scientific Research | Bouley S.,University Paris - Sud | And 58 more authors.
Experimental Astronomy | Year: 2014

Amateur contributions to professional publications have increased exponentially over the last decades in the field of planetary astronomy. Here we review the different domains of the field in which collaborations between professional and amateur astronomers are effective and regularly lead to scientific publications.We discuss the instruments, detectors, software and methodologies typically used by amateur astronomers to collect the scientific data in the different domains of interest. Amateur contributions to the monitoring of planets and interplanetary matter, characterization of asteroids and comets, as well as the determination of the physical properties of Kuiper Belt Objects and exoplanets are discussed. © 2014, Springer Science+Business Media Dordrecht.

Moutou C.,Aix - Marseille University | Diaz R.F.,University Pierre and Marie Curie | Diaz R.F.,French National Center for Scientific Research | Udry S.,Observatoire de Geneva | And 27 more authors.
Astronomy and Astrophysics | Year: 2011

We report the measurement of the spin-orbit angle of the extra-solar planets HAT-P-8 b, HAT-P-9 b, HAT-P-16 b, and HAT-P-23 b, based on spectroscopic observations performed at the Observatoire de Haute-Provence with the SOPHIE spectrograph on the 1.93-m telescope. Radial velocity measurements of the Rossiter-McLaughlin effect show the detection of an apparent prograde, aligned orbit for all systems. The projected spin-orbit angles are found to be λ =-17°+9.2 -11.5-16° ± 8°,-10° ± 16°, and +15° ± 22° for HAT-P-8, HAT-P-9, HAT-P-16, and HAT-P-23, respectively, with corresponding projected rotational velocities of 14.5 ± 0.8, 12.5 ± 1.8, 3.9 ± 0.8, and 7.8 ± 1.6 kms-1. These new results increase to 37 the number of accurately measured spin-orbit angles in transiting extrasolar systems. We conclude by drawing a tentative picture of the global behaviour of orbital alignement, involving the complexity and diversity of possible mechanisms. © 2011 ESO.

Santerne A.,University of Porto | Santerne A.,Aix - Marseille University | Hebrard G.,University Pierre and Marie Curie | Hebrard G.,French National Center for Scientific Research | And 46 more authors.
Astronomy and Astrophysics | Year: 2014

In this paper we report a new transiting warm giant planet: KOI-1257 b. It was first detected in photometry as a planet-candidate by the Kepler space telescope and then validated thanks to a radial velocity follow-up with the SOPHIE spectrograph. It orbits its host star with a period of 86.647661 d3 s and a high eccentricity of 0.7720.045. The planet transits the main star of a metal-rich, relatively old binary system with stars of mass of 0.99 0.05 M and 0.70 ± 0.07 M for the primary and secondary, respectively. This binary system is constrained thanks to a self-consistent modelling of the Kepler transit light curve, the SOPHIE radial velocities, line bisector and full-width half maximum (FWHM) variations, and the spectral energy distribution. However, future observations are needed to confirm it. The PASTIS fully-Bayesian software was used to validate the nature of the planet and to determine which star of the binary system is the transit host. By accounting for the dilution from the binary both in photometry and in radial velocity, we find that the planet has a mass of 1.45 ± 0.35 M, and a radius of 0.94 ± 0.12 R™, and thus a bulk density of 2.1 ± 1.2 g cm-3. The planet has an equilibrium temperature of 511 50 K, making it one of the few known members of the warm-Jupiter population. The HARPS-N spectrograph was also used to observe a transit of KOI-1257 b, simultaneously with a joint amateur and professional photometric follow-up, with the aim of constraining the orbital obliquity of the planet. However, the Rossiter-McLaughlin effect was not clearly detected, resulting in poor constraints on the orbital obliquity of the planet. © 2014 ESO.

Bonomo A.S.,Aix - Marseille University | Hebrard G.,University Pierre and Marie Curie | Hebrard G.,Aix - Marseille University | Santerne A.,Aix - Marseille University | And 9 more authors.
Astronomy and Astrophysics | Year: 2012

We report the discovery of two new transiting hot Jupiters, KOI-135b and KOI-204b, which were previously identified as planetary candidates by the Kepler team, and independently confirm the planetary nature of Kepler-17b, recently announced by Désert et al. (2011, ApJS, 197, 14). Radial-velocity measurements, taken with the SOPHIE spectrograph at the Observatoire de Haute-Provence (France), and Kepler photometry (Q1 and Q2 data) were used to derive the orbital, stellar, and planetary parameters. KOI-135b and KOI-204b orbit their parent stars in -3.02 and 3.25 days, respectively. They have approximately the same radius, R p = 1.20 ± 0.06 R Jup and 1.24 ± 0.07 R Jup, but different masses M p = 3.23 ± 0.19 M Jup and 1.02 ± 0.07 M Jup. As a consequence, their bulk densities differ by a factor of four, ρ p = 2.33 ± 0.36 g cm -3 (KOI-135b) and 0.65 ± 0.12 g cm -3 (KOI-204b), meaning that their interior structures are different. All three planets orbit metal-rich stars with [Fe/H] - 0.3 dex. Our SOPHIE spectra of Kepler-17 were used both to measure the radial-velocity variations and to determine the stellar atmospheric parameters, allowing us to refine the characterisation of the planetary system. In particular we found the radial-velocity semi-amplitude and the stellar mass to be respectively slightly smaller and larger than in Désert et al. These two quantities, however, compensate and lead to a fully consistent planetary mass. Our analysis gives M p = 2.47 ± 0.10 M Jup and R p = 1.33 ± 0.04 R Jup. We found evidence of a younger age for this planetary system, t < 1.8 Gyr, which is supported by both evolutionary tracks and gyrochronology. Finally, we confirm the detection of the optical secondary eclipse by Désert et al. and also find the brightness phase variation with the Q1 and Q2 Kepler data. The latter indicates a low redistribution of stellar heat to the night side (<16% at 1-σ), if the optical planetary occultation comes entirely from thermal flux. The geometric albedo is A g < 0.12 (1-σ). © ESO, 2012.

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