References of "Queloz, D"
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See detailDiscovery of WASP-65b and WASP-75b: Two Hot Jupiters Without Highly Inflated Radii
Gómez Maqueo Chew, Y.; Faedi, F.; Pollacco, D. et al

in Astronomy and Astrophysics (2013)

We report the discovery of two transiting hot Jupiters, WASP-65b (Mpl = 1.55 ± 0.16 MJ; Rpl = 1.11 ± 0.06 RJ), and WASP-75b (Mpl = 1.07 ± 0.05 MJ; Rpl = 1.27 ± 0.05 RJ). They orbit their host star every ... [more ▼]

We report the discovery of two transiting hot Jupiters, WASP-65b (Mpl = 1.55 ± 0.16 MJ; Rpl = 1.11 ± 0.06 RJ), and WASP-75b (Mpl = 1.07 ± 0.05 MJ; Rpl = 1.27 ± 0.05 RJ). They orbit their host star every ~2.311, and ~2.484 days, respectively. The planet host WASP-65 is a G6 star (Teff = 5600 K, [Fe/H] = -0.07 ± 0.07, age ≳8 Gyr); WASP-75 is an F9 star (Teff = 6100 K, [Fe/H] = 0.07 ± 0.09, age ~ 3 Gyr). WASP-65b is one of the densest known exoplanets in the mass range 0.1 and 2.0 MJ (rhopl = 1.13 ± 0.08 rhoJ), a mass range where a large fraction of planets are found to be inflated with respect to theoretical planet models. WASP-65b is one of only a handful of planets with masses of ~1.5 MJ, a mass regime surprisingly underrepresented among the currently known hot Jupiters. The radius of WASP-75b is slightly inflated (≲10%) as compared to theoretical planet models with no core, and has a density similar to that of Saturn (rhopl = 0.52 ± 0.06 rhoJ). [less ▲]

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See detailThree irradiated and bloated hot Jupiters: WASP-76b, WASP-82b & WASP-90b
West, R. G.; Almenara, J.-M.; Anderson, D. R. et al

E-print/Working paper (2013)

We report three new transiting hot-Jupiter planets discovered from the WASP surveys combined with radial velocities from OHP/SOPHIE and Euler/CORALIE and photometry from Euler and TRAPPIST. All three ... [more ▼]

We report three new transiting hot-Jupiter planets discovered from the WASP surveys combined with radial velocities from OHP/SOPHIE and Euler/CORALIE and photometry from Euler and TRAPPIST. All three planets are inflated, with radii 1.7-1.8 Rjup. All orbit hot stars, F5-F7, and all three stars have evolved, post-MS radii (1.7-2.2 Rsun). Thus the three planets, with orbits of 1.8-3.9 d, are among the most irradiated planets known. This reinforces the correlation between inflated planets and stellar irradiation. [less ▲]

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See detailTowards the first transmission spectrum of a gas giant transiting an M-dwarf
Delrez, Laetitia ULg; Gillon, Michaël ULg; Lendl, M. et al

Poster (2013, July 15)

At the forefront of comparative exoplanetology, the atmospheric characterization of transiting exoplanets is revealing the intimate nature of these new worlds. In this exciting context, we are currently ... [more ▼]

At the forefront of comparative exoplanetology, the atmospheric characterization of transiting exoplanets is revealing the intimate nature of these new worlds. In this exciting context, we are currently conducting a VLT observing campaign on a rare exoplanet specimen, WASP-80b, a gas giant in close orbit around a bright nearby M-dwarf. Even if this planet belongs to the hot-Jupiter population, it is actually more ‘warm’ than ‘hot’ with an estimated equilibrium temperature of only 800K. We present here some preliminary results of this program which consists in monitoring four transits of WASP-80b with the FORS2 instrument in multi-object spectroscopic mode in ESO phase 91. Through this approach, our goal is to precisely measure the transmission spectrum of the planet between 740 and 1070 nm in order to constrain the thermal structure and scacering properties of the planetary atmosphere. Furthermore, we will use the water features located around 950 nm to constrain the water mixing ratio in the atmosphere of this peculiar hot Jupiter. [less ▲]

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See detailFast-evolving weather for the coolest of our two new substellar neighbours
Gillon, Michaël ULg; Triaud, A. H. M. J.; Jehin, Emmanuel ULg et al

in Astronomy and Astrophysics (2013), 555

We present the results of an intense photometric monitoring in the near-infrared (~0.9 microns) with the TRAPPIST robotic telescope of the newly discovered binary brown dwarf WISE J104915.57-531906.1, the ... [more ▼]

We present the results of an intense photometric monitoring in the near-infrared (~0.9 microns) with the TRAPPIST robotic telescope of the newly discovered binary brown dwarf WISE J104915.57-531906.1, the third closest system to the Sun at a distance of only 2 pc. Our twelve nights of photometric time-series reveal a quasi-periodic (P = 4.87+-0.01 h) variability with a maximal peak-peak amplitude of ~11% and strong night-to-night evolution. We attribute this variability to the rotational modulation of fast-evolving weather patterns in the atmosphere of the coolest component (~T1-type) of the binary. No periodic signal is detected for the hottest component (~L8-type). For both brown dwarfs, our data allow us to firmly discard any unique transit during our observations for planets >= 2 Rearth. For orbital periods smaller than ~9.5 h, transiting planets are excluded down to an Earth-size. [less ▲]

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See detailTransiting exoplanets from the CoRoT space mission. XXIV. CoRoT-25b and CoRoT-26b: two low-density giant planets
Almenara, J. M.; Bouchy, F.; Gaulme, P. et al

in Astronomy and Astrophysics (2013), 555

We report the discovery of two transiting exoplanets, CoRoT-25b and CoRoT-26b, both of low density, one of which is in the Saturn mass-regime. For each star, ground-based complementary observations ... [more ▼]

We report the discovery of two transiting exoplanets, CoRoT-25b and CoRoT-26b, both of low density, one of which is in the Saturn mass-regime. For each star, ground-based complementary observations through optical photometry and radial velocity measurements secured the planetary nature of the transiting body and allowed us to fully characterize them. For CoRoT-25b we found a planetary mass of 0.27 ± 0.04 M[SUB]Jup[/SUB], a radius of 1.08[SUB]-0.10[/SUB][SUP]+0.3[/SUP] R[SUB]Jup[/SUB] and hence a mean density of 0.15[SUB]-0.06[/SUB][SUP]+0.15[/SUP] g cm[SUP]-3[/SUP]. The planet orbits an F9 main-sequence star in a 4.86-day period, that has a V magnitude of 15.0, solar metallicity, and an age of 4.5[SUB]-2.0[/SUB][SUP]+1.8[/SUP]-Gyr. CoRoT-26b orbits a slightly evolved G5 star of 9.06 ± 1.5-Gyr age in a 4.20-day period that hassolar metallicity and a V magnitude of 15.8. With a mass of 0.52 ± 0.05 M[SUB]Jup[/SUB], a radius of 1.26[SUB]-0.07[/SUB][SUP]+0.13[/SUP] R[SUB]Jup[/SUB], and a mean density of 0.28[SUB]-0.07[/SUB][SUP]+0.09[/SUP] g cm[SUP]-3[/SUP], it belongs to the low-mass hot-Jupiter population. Planetary evolution models allowed us to estimate a core mass of a few tens of Earth mass for the two planets with heavy-element mass fractions of 0.52[SUB]-0.15[/SUB][SUP]+0.08[/SUP] and 0.26[SUB]-0.08[/SUB][SUP]+0.05[/SUP], respectively, assuming that a small fraction of the incoming flux is dissipated at the center of the planet. In addition, these models indicate that CoRoT-26b is anomalously large compared with what standard models could account for, indicating that dissipation from stellar heating could cause this size. The CoRoT space mission, launched on December 27th 2006, has been developed and is operated by CNES, with the contribution of Austria, Belgium, Brazil, ESA (RSSD and Science Programme), Germany and Spain. Partly based on observations obtained at the European Southern Observatory at Paranal and La Silla, Chile in programs 083.C-0690(A), 184.C-0639. [less ▲]

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See detailThe HARPS search for southern extra-solar planets. XXXIV. A planetary system around the nearby M dwarf GJ163, with a super-Earth possibly in the habitable zone
Bonfils, X.; Lo Curto, G.; Correia, A. C. M. et al

E-print/Working paper (2013)

The meter-per-second precision achieved by today velocimeters enables the search for 1-10 M_Earth planets in the habitable zone of cool stars. This paper reports on the detection of 3 planets orbiting ... [more ▼]

The meter-per-second precision achieved by today velocimeters enables the search for 1-10 M_Earth planets in the habitable zone of cool stars. This paper reports on the detection of 3 planets orbiting GJ163 (HIP19394), a M3 dwarf monitored by our ESO/HARPS search for planets. We made use of the HARPS spectrograph to collect 150 radial velocities of GJ163 over a period of 8 years. We searched the RV time series for coherent signals and found 5 distinct periodic variabilities. We investigated the stellar activity and casted doubts on the planetary interpretation for 2 signals. Before more data can be acquired we concluded that at least 3 planets are orbiting GJ163. They have orbital periods of P_b=8.632+-0.002, P_c=25.63+-0.03 and P_d=604+-8 days and minimum masses msini = 10.6+-0.6, 6.8+-0.9, and 29+-3 M_Earth, respectively. We hold our interpretations for the 2 additional signals with periods P_(e)=19.4 and P_(f)=108 days. The inner pair presents an orbital period ratio of 2.97, but a dynamical analysis of the system shows that it lays outside the 3:1 mean motion resonance. GJ163c, in particular, is a super-Earth with an equilibrium temperature of T_eq = (302+-10) (1-A)^(1/4) K and may lie in the so called habitable zone for albedo values (A=0.34-0.89) moderately higher than that of Earth (A_Earth=0.2-0.3). [less ▲]

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See detailWarm Spitzer Occultation Photometry of WASP-26b at 3.6{\mu}m and 4.5{\mu}m
Mahtani, D. P.; Maxted, P. F. L.; Anderson, D. R. et al

in Monthly Notices of the Royal Astronomical Society (2013), 432(1), 693-701

We present new warm Spitzer occultation photometry of WASP-26 at 3.6{\mu}m and 4.5{\mu}m along with new transit photometry taken in the g,r and i bands. We report the first detection of the occultation of ... [more ▼]

We present new warm Spitzer occultation photometry of WASP-26 at 3.6{\mu}m and 4.5{\mu}m along with new transit photometry taken in the g,r and i bands. We report the first detection of the occultation of WASP-26b, with occultation depths at 3.6{\mu}m and 4.5{\mu}m of 0.00126 +/- 0.00013 and 0.00149 +/- 0.00016 corresponding to brightness temperatures of 1825+/-80K and 1725+/-89K, respectively. We find that the eccentricity of the orbit is consistent with a circular orbit at the 1{\sigma} level with a 3{\sigma} upper limit of e < 0.04. According to the activity-inversion relation of Knutson et al. (2010), WASP-26b is predicted to host a thermal inversion. The brightness temperatures deduced from the eclipse depths are consistent with an isothermal atmosphere, although it is within the uncertainties that the planet may host a weak thermal inversion. The data are equally well fit by atmospheric models with or without a thermal inversion. We find that variation in activity of solar-like stars does not change enough over the time-scales of months or years to change the interpretation of the Knutson et al. (2010) activity-inversion relation, provided that the measured activity level is averaged over several nights. Further data are required to fully constrain the thermal structure of the atmosphere because the planet lies very close to the boundary between atmospheres with and without a thermal inversion. [less ▲]

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See detailCHEOPS: A transit photometry mission for ESA's small mission programme
Broeg, C.; Fortier, A.; Ehrenreich, D. et al

in Saglia, Roberto (Ed.) European Physical Journal Web of Conferences (2013, April 01)

Ground based radial velocity (RV) searches continue to discover exoplanets below Neptune mass down to Earth mass. Furthermore, ground based transit searches now reach milli-mag photometric precision and ... [more ▼]

Ground based radial velocity (RV) searches continue to discover exoplanets below Neptune mass down to Earth mass. Furthermore, ground based transit searches now reach milli-mag photometric precision and can discover Neptune size planets around bright stars. These searches will find exoplanets around bright stars anywhere on the sky, their discoveries representing prime science targets for further study due to the proximity and brightness of their host stars. A mission for transit follow-up measurements of these prime targets is currently lacking. The first ESA S-class mission CHEOPS (CHaracterizing ExoPlanet Satellite) will fill this gap. It will perform ultra-high precision photometric monitoring of selected bright target stars almost anywhere on the sky with sufficient precision to detect Earth sized transits. It will be able to detect transits of RV-planets by photometric monitoring if the geometric configuration results in a transit. For Hot Neptunes discovered from the ground, CHEOPS will be able to improve the transit light curve so that the radius can be determined precisely. Because of the host stars' brightness, high precision RV measurements will be possible for all targets. All planets observed in transit by CHEOPS will be validated and their masses will be known. This will provide valuable data for constraining the mass-radius relation of exoplanets, especially in the Neptune-mass regime. During the planned 3.5 year mission, about 500 targets will be observed. There will be 20% of open time available for the community to develop new science programmes. [less ▲]

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See detailTRAPPIST-UCDTS: A prototype search for habitable planets transiting ultra-cool stars
Gillon, Michaël ULg; Jehin, Emmanuel ULg; Fumel, A. et al

in Saglia, Roberto (Ed.) European Physical Journal Web of Conferences (2013, April 01)

The ˜1000 nearest ultra-cool stars (spectral type M6 and latter) represent a unique opportunity for the search for life outside solar system. Due to their small luminosity, their habitable zone is 30-100 ... [more ▼]

The ˜1000 nearest ultra-cool stars (spectral type M6 and latter) represent a unique opportunity for the search for life outside solar system. Due to their small luminosity, their habitable zone is 30-100 times closer than for the Sun, the corresponding orbital periods ranging from one to a few days. Thanks to this proximity, the transits of a habitable planet are much more probable and frequent than for an Earth-Sun analog, while their tiny size (˜1 Jupiter radius) leads to transits deep enough for a ground-based detection, even for sub-Earth size planets. Furthermore, a habitable planet transiting one of these nearby ultra-cool star would be amenable for a thorough atmospheric characterization, including the detection of possible biosignatures, notably with the near-to-come JWST. Motivated by these reasons, we have set up the concept of a ground-based survey optimized for detecting planets of Earth-size and below transiting the nearest Southern ultra-cool stars. To assess thoroughly the actual potential of this future survey, we are currently conducting a prototype mini-survey using the TRAPPIST robotic 60cm telescope located at La Silla ESO Observatory (Chile). We summarize here the preliminary results of this mini-survey that fully validate our concept. [less ▲]

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See detailThermal emission at 3.6-8 micron from WASP-19b: a hot Jupiter without a stratosphere orbiting an active star
Anderson, D. R.; Smith, A. M. S.; Madhusudhan, N. et al

in Monthly Notices of the Royal Astronomical Society (2013), 430(4), 3422-3431

We report detection of thermal emission from the exoplanet WASP-19b at 3.6, 4.5, 5.8 and 8.0 μm. We used the InfraRed Array Camera on the Spitzer Space Telescope to observe two occultations of WASP-19b by ... [more ▼]

We report detection of thermal emission from the exoplanet WASP-19b at 3.6, 4.5, 5.8 and 8.0 μm. We used the InfraRed Array Camera on the Spitzer Space Telescope to observe two occultations of WASP-19b by its host star. We combine our new detections with previous measurements of WASP-19b's emission at 1.6 and 2.09 μm to construct a spectral energy distribution of the planet's dayside atmosphere. By comparing this with model-atmosphere spectra, we find that the dayside atmosphere of WASP-19b lacks a strong temperature inversion. As WASP-19 is an active star (log R'HK = -4.50 ± 0.03), this finding supports the hypothesis of Knutson, Howard and Isaacson that inversions are suppressed in hot Jupiters orbiting active stars. The available data are unable to differentiate between a carbon-rich and an oxygen-rich atmosphere. [less ▲]

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See detailWASP-64b and WASP-72b: two new transiting highly irradiated giant planets
Gillon, Michaël ULg; Anderson, D. R.; Collier-Cameron, A. et al

in Astronomy and Astrophysics (2013), 552

We report the discovery by the WASP transit survey of two new highly irradiated giant planets. WASP-64 b is slightly more massive (1.271 ± 0.068 MJup) and larger (1.271 ± 0.039 RJup) than Jupiter, and is ... [more ▼]

We report the discovery by the WASP transit survey of two new highly irradiated giant planets. WASP-64 b is slightly more massive (1.271 ± 0.068 MJup) and larger (1.271 ± 0.039 RJup) than Jupiter, and is in very-short (a = 0.02648 ± 0.00024 AU, P = 1.5732918 ± 0.0000015 days) circular orbit around a V = 12.3 G7-type dwarf (1.004 ± 0.028 Msun, 1.058 ± 0.025 Rsun, Teff = 5500 ± 150 K). Its size is typical of hot Jupiters with similar masses. WASP-72 b has also a mass a bit higher than Jupiter's (1.461-0.056+0.059 MJup) and orbits very close (0.03708 ± 0.00050 AU, P = 2.2167421 ± 0.0000081 days) to a bright (V = 9.6) and moderately evolved F7-type star (1.386 ± 0.055 Msun, 1.98 ± 0.24 Rsun, Teff = 6250 ± 100 K). Despite its extreme irradiation (~5.5 × 109 erg s-1 cm-2), WASP-72 b has a moderate size (1.27 ± 0.20 RJup) that could suggest a significant enrichment in heavy elements. Nevertheless, the errors on its physical parameters are still too high to draw any strong inference on its internal structure or its possible peculiarity. [less ▲]

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See detailSearching for water in the atmosphere of the hot Saturn WASP-49b
Delrez, Laetitia ULg; Lendl, M.; Gillon, Michaël ULg et al

Poster (2013, March 11)

At the forefront of comparative exoplanetology, the atmospheric characterization of transiting exoplanets is revealing the intimate nature of these 'new worlds'. In this exciting context, we present here ... [more ▼]

At the forefront of comparative exoplanetology, the atmospheric characterization of transiting exoplanets is revealing the intimate nature of these 'new worlds'. In this exciting context, we present here some preliminary results of our VLT program that consisted in monitoring three transits of the new 'hot Saturn' WASP-49b (Lendl et al. 2012) with the FORS instrument in Multi-Object Spectroscopic mode (MXU). [less ▲]

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See detailWASP-54b, WASP-56b and WASP-57b: Three new sub-Jupiter mass planets from SuperWASP
Faedi, F.; Pollacco, D.; Barros, S. C. C. et al

in Astronomy and Astrophysics (2013), 551

We present three newly discovered sub-Jupiter mass planets from the SuperWASP survey: WASP-54b is a heavily bloated planet of mass 0.636+0.025-0.024RJ. It orbits a F9 star, evolving off the main sequence ... [more ▼]

We present three newly discovered sub-Jupiter mass planets from the SuperWASP survey: WASP-54b is a heavily bloated planet of mass 0.636+0.025-0.024RJ. It orbits a F9 star, evolving off the main sequence, every 3.69 days. Our MCMC fit of the system yields a slightly eccentric orbit (e = 0.067+0.033-0.025) for WASP-54b. We investigated further the veracity of our detection of the eccentric orbit for WASP-54b, and we find that it could be real. However, given the brightness of WASP-54 V = 10.42 mag, we encourage observations of a secondary eclipse to draw robust conclusions on both the orbital eccentricity and the thermal structure of the planet. WASP-56b and WASP-57b have masses of 0.571+0.034-0.035MJ and 0.672+0.049-0.046MJ, respectively; and radii of 1.092+0.035-0.033RJ for WASP-56b and 0.916+0.017-0.014RJ for WASP-57b. They orbit main sequence stars of spectral type G6 every 4.67 and 2.84 days, respectively. WASP-56b and WASP-57b show no radius anomaly and a high density possibly implying a large core of heavy elements; possibly as high as ~50 M⊕ in the case of WASP-57b. However,the composition of the deep interior of exoplanets remains still undetermined. Thus, more exoplanet discoveries such as the ones presented in this paper, are needed to understand and constrain giant planets' physical properties. [less ▲]

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See detailThe CORALIE survey for southern extrasolar planets XVII. New and updated long period and massive planets
Marmier, M.; Ségransan, D.; Udry, S. et al

in Astronomy and Astrophysics (2013), 551

Context. Since 1998, a planet-search program around main sequence stars within 50 pc in the southern hemisphere has been carried out with the CORALIE echelle spectrograph at La Silla Observatory. Aims ... [more ▼]

Context. Since 1998, a planet-search program around main sequence stars within 50 pc in the southern hemisphere has been carried out with the CORALIE echelle spectrograph at La Silla Observatory. Aims: With an observing time span of more than 14 years, the CORALIE survey is now able to unveil Jovian planets on Jupiter's period domain. This growing period-interval coverage is important for building formation and migration models since observational constraints are still weak for periods beyond the ice line. Methods: Long-term precise Doppler measurements with the CORALIE echelle spectrograph, together with a few additional observations made with the HARPS spectrograph on the ESO 3.6 m telescope, reveal radial velocity signatures of massive planetary companions on long-period orbits. Results: In this paper we present seven new planets orbiting HD 27631, HD 98649, HD 106515A, HD 166724, HD 196067, HD 219077, and HD 220689, together with the CORALIE orbital parameters for three already known planets around HD 10647, HD 30562, and HD 86226. The period range of the new planetary companions goes from 2200 to 5500 days and covers a mass domain between 1 and 10.5 MJup. Surprisingly, five of them present very high eccentricities above e > 0.57. A pumping scenario by Kozai mechanism may be invoked for HD 106515Ab and HD 196067b, which are both orbiting stars in multiple systems. Since the presence of a third massive body cannot be inferred from the data of HD 98649b, HD 166724b, and HD 219077b, the origin of the eccentricity of these systems remains unknown. Except for HD 10647b, no constraint on the upper mass of the planets is provided by Hipparcos astrometric data. Finally, the hosts of these long period planets show no metallicity excess. [less ▲]

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See detailWASP-80b: a gas giant transiting a cool dwarf
Triaud, A. H. M. J.; Anderson, D. R.; Collier Cameron, A. et al

in Astronomy and Astrophysics (2013), 551

We report the discovery of a planet transiting the star <ASTROBJ>WASP-80</ASTROBJ> (<ASTROBJ>1SWASP J201240.26-020838.2</ASTROBJ>; <ASTROBJ>2MASS J20124017-0208391</ASTROBJ>; <ASTROBJ>TYC 5165-481-1 ... [more ▼]

We report the discovery of a planet transiting the star <ASTROBJ>WASP-80</ASTROBJ> (<ASTROBJ>1SWASP J201240.26-020838.2</ASTROBJ>; <ASTROBJ>2MASS J20124017-0208391</ASTROBJ>; <ASTROBJ>TYC 5165-481-1</ASTROBJ>; <ASTROBJ>BPM 80815</ASTROBJ>; V = 11.9, K = 8.4). Our analysis shows this is a 0.55 ± 0.04 M[SUB]jup[/SUB], 0.95 ± 0.03 R[SUB]jup[/SUB] gas giant on a circular 3.07 day orbit around a star with a spectral type between K7V and M0V. This system produces one of the largest transit depths so far reported, making it a worthwhile target for transmission spectroscopy. We find a large discrepancy between the vsini[SUB]⋆[/SUB] inferred from stellar line broadening and the observed amplitude of the Rossiter-McLaughlin effect. This can be understood either by an orbital plane nearly perpendicular to the stellar spin or by an additional, unaccounted for source of broadening. Using WASP-South photometric observations, from Sutherland (South Africa), confirmed with the 60 cm TRAPPIST robotic telescope, EulerCam, and the CORALIE spectrograph on the Swiss 1.2 m Euler Telescope, and HARPS on the ESO 3.6 m (Prog ID 089.C-0151), all three located at La Silla Observatory, Chile.Radial velocity and photometric data are available in electronic form at the CDS via anonymous ftp to <A href="http://cdsarc.u-strasbg.fr">cdsarc.u-strasbg.fr</A>(<A href="http://130.79.128.5">130.79.128.5</A>) or via <A href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/551/A80">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/551/A80</A> [less ▲]

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See detailAccurate spectroscopic parameters of WASP planet host stars
Doyle, Amanda P.; Smalley, B.; Maxted, P. F. L. et al

in Monthly Notices of the Royal Astronomical Society (2013), 428(4), 3164-3172

We have made a detailed spectral analysis of eleven Wide Angle Search for Planets (WASP) planet host stars using high signal-to-noise (S/N) HARPS spectra. Our line list was carefully selected from the ... [more ▼]

We have made a detailed spectral analysis of eleven Wide Angle Search for Planets (WASP) planet host stars using high signal-to-noise (S/N) HARPS spectra. Our line list was carefully selected from the spectra of the Sun and Procyon, and we made a critical evaluation of the atomic data. The spectral lines were measured using equivalent widths. The procedures were tested on the Sun and Procyon prior to be being used on the WASP stars. The effective temperature, surface gravity, microturbulent velocity and metallicity were determined for all the stars. We show that abundances derived from high S/N spectra are likely to be higher than those obtained from low S/N spectra, as noise can cause the equivalent width to be underestimated. We also show that there is a limit to the accuracy of stellar parameters that can be achieved, despite using high S/N spectra, and the average uncertainty in effective temperature, surface gravity, microturbulent velocity and metallicity is 83 K, 0.11 dex, 0.11 km/s and 0.10 dex respectively. [less ▲]

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See detailWASP-77 Ab: A Transiting Hot Jupiter Planet in a Wide Binary System
Maxted, P. F. L.; Anderson, D. R.; Collier Cameron, A. et al

in Publications of the Astronomical Society of the Pacific (2013), 125

We report the discovery of a transiting planet with an orbital period of 1.36 days orbiting the brighter component of the visual binary star BD 07 436. The host star, WASP-77 A, is a moderately bright G8 ... [more ▼]

We report the discovery of a transiting planet with an orbital period of 1.36 days orbiting the brighter component of the visual binary star BD 07 436. The host star, WASP-77 A, is a moderately bright G8 V star (V=10.3) with a metallicity close to solar ([Fe/H] = 0.0 ± 0.1). The companion star, WASP-77 B, is a K-dwarf approximately 2 mag fainter at a separation of approximately 3″. The spectrum of WASP-77 A shows emission in the cores of the Caii H and K lines, indicative of moderate chromospheric activity. The Wide Angle Search for Planets (WASP) light curves show photometric variability with a period of 15.3 days and an amplitude of about 0.3% that is probably due to the magnetic activity of the host star. We use an analysis of the combined photometric and spectroscopic data to derive the mass and radius of the planet (1.76 ± 0.06 M[SUB]Jup[/SUB], 1.21 ± 0.02 R[SUB]Jup[/SUB]). The age of WASP-77 A estimated from its rotation rate (˜1 Gyr) agrees with the age estimated in a similar way for WASP-77 B (˜0.6 Gyr) but is in poor agreement with the age inferred by comparing its effective temperature and density to stellar models (˜8 Gyr). Follow-up observations of WASP-77 Ab will make a useful contribution to our understanding of the influence of binarity and host star activity on the properties of hot Jupiters. [less ▲]

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See detailThe HARPS search for southern extra-solar planets: XXXI. The M-dwarf sample
Bonfils, X.; Delfosse, X.; Udry, S. et al

in Astronomy and Astrophysics (2013), 549

(Abridged) Searching for planets around stars with different masses probes the outcome of planetary formation for different initial conditions. This drives observations of a sample of 102 southern nearby ... [more ▼]

(Abridged) Searching for planets around stars with different masses probes the outcome of planetary formation for different initial conditions. This drives observations of a sample of 102 southern nearby M dwarfs, using a fraction of our guaranteed time on the ESO/HARPS spectrograph (Feb. 11th, 2003 to Apr. 1st 2009). This paper makes available the sample's time series, presents their precision and variability. We apply systematic searches and diagnostics to discriminate whether the observed Doppler shifts are caused by stellar surface inhomogeneities or by the radial pull of orbiting planets. We recover the planetary signals corresponding to 9 planets already announced by our group (Gl176b, Gl581b, c, d & e, Gl674b, Gl433b, Gl 667Cb and c). We present radial velocities that confirm GJ 849 hosts a Jupiter-mass planet, plus a long-term radial-velocity variation. We also present RVs that precise the planetary mass and period of Gl 832b. We detect long-term RV changes for Gl 367, Gl 680 and Gl 880 betraying yet unknown long-period companions. We identify candidate signals in the radial-velocity time series and demonstrate they are most probably caused by stellar surface inhomogeneities. Finally, we derive a first estimate of the occurrence of M-dwarf planets as a function of their minimum mass and orbital period. In particular, we find that giant planets (m sin i = 100-1,000 Mearth) have a low frequency (e.g. f<1% for P=1-10 d and f=0.02^{+0.03}_{-0.01} for P=10-100 d), whereas super-Earths (m sin i = 1-10 Mearth) are likely very abundant (f=0.36^{+0.25}_{-0.10} for P=1-10 d and f=0.35^{+0.45}_{-0.11} for P=10-100 d). We also obtained eta_earth=0.41^{+0.54}_{-0.13}, the frequency of habitable planets orbiting M dwarfs (1<m sin i<10 Mearth). For the first time, eta_earth is a direct measure and not a number extrapolated from the statistic of more massive and/or shorter-period planets. [less ▲]

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See detailTowards a Transmission Spectrum of the Hot Saturn WASP-49b
Lendl, Monika ULg; Delrez, Laetitia ULg; Gillon, Michaël ULg et al

Poster (2013)

Transiting extrasolar planets are so far the only planets for which atmospheres can be studied in detail. The spectro-photometric observation of transits allows to search for wavelength dependencies in ... [more ▼]

Transiting extrasolar planets are so far the only planets for which atmospheres can be studied in detail. The spectro-photometric observation of transits allows to search for wavelength dependencies in the effective planetary radius that are sensitive to signatures of chemical elements in the planetary atmosphere. We present first results from an observing campaign carried out using the FORS2 instrument to obtain spectro-photometric observations of transits of the low-density hot Saturn WASP-49b. [less ▲]

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See detailStudying the Atmospheres of the Most Intriguing WASP Hot Jupiters
Lendl, Monika ULg; Delrez, Laetitia ULg; Gillon, Michaël ULg et al

Conference (2013)

Among the over 300 transiting planets confirmed to date, approximately 130 have been found by groundbased wide angle transit surveys such asWASP. While these surveys are not sensitive enough to detect ... [more ▼]

Among the over 300 transiting planets confirmed to date, approximately 130 have been found by groundbased wide angle transit surveys such asWASP. While these surveys are not sensitive enough to detect lowmass planets, they excel at picking out rare hot- Jupiters orbiting reasonably bright stars (V mag = 9 - 11) across the sky. These planets occupy a favorable region in parameter space, as they show frequent and deep transits. Due to the proximity to their host stars these gas giants possess hot extended atmospheres making them ideal targets for the study of their atmospheres via transmission and occultation spectrophotometry. During occultation, the flux emerging from the planetary dayside is eliminated. By comparing the flux in- and out-of occultation, the planet-to-star brightness ratio can be measured. Observations in different passbands yield a measure of the planetary spectral energy distribution and thereby allow to determine the atmospheric temperature structure, heat redistribution efficiency, albedo, and to place constraints on the atmospheric composition. From the spectro-photometric observation of transits, we can measure wavelength dependencies in the effective planetary radius that are sensitive to signatures of chemical elements in the planetary atmosphere. We present results of ongoing observing campaigns employing these methods to study the atmospheres of hot Jupiters discovered by the WASP survey. In particular we show results for the very short-period planet WASP-19b based on data from the 1m-class Euler-Swiss and TRAPPIST telescopes, as well as a transmission spectrum of the low-density hot Saturn WASP-49b obtained from FORS2 at the VLT/UT1. [less ▲]

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