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See detailThe HARPS search for southern extra-solar planets XXXII. Only 4 planets in the Gl~581 system
Forveille, T.; Bonfils, X.; Delfosse, X. et al

E-print/Working paper (2011)

The Gl 581 planetary system has generated wide interest, because its 4 planets include both the lowest mass planet known around a main sequence star other than the Sun and the first super-Earth planet in ... [more ▼]

The Gl 581 planetary system has generated wide interest, because its 4 planets include both the lowest mass planet known around a main sequence star other than the Sun and the first super-Earth planet in the habitable zone of its star. A recent paper announced the possible discovery of two additional super-Earth planets in that system, one of which would be in the middle of the habitable zone of Gl 581. The statistical significance of those two discoveries has, however, been questioned. We have obtained 121 new radial velocity measurements of Gl 581 with the HARPS spectrograph on the ESO 3.6 m telescope, and analyse those together with our previous 119 measurements of that star to examine these potential additional planets. We find that neither is likely to exist with their proposed parameters. We also obtained photometric observations with the 2.5 m Isaac Newton Telescope during a potential transit of the inner planet, Gl 581e, which had a 5% geometric transit probability. Those observations exclude transits for planet densities under 4 times the Earth density within -0.2 sigma to +2.7 sigma of the predicted transit center. [less ▲]

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See detailTransiting exoplanets from the CoRoT space mission. XVIII. CoRoT-18b: a massive hot Jupiter on a prograde, nearly aligned orbit
Hébrard, G.; Evans, T. M.; Alonso, R. et al

in Astronomy and Astrophysics (2011), 533

We report the detection of CoRoT-18b, a massive hot Jupiter transiting in front of its host star with a period of 1.9000693 ± 0.0000028 days. This planet was discovered thanks to photometric data secured ... [more ▼]

We report the detection of CoRoT-18b, a massive hot Jupiter transiting in front of its host star with a period of 1.9000693 ± 0.0000028 days. This planet was discovered thanks to photometric data secured with the CoRoT satellite combined with spectroscopic and photometric ground-based follow-up observations. The planet has a mass M[SUB]p[/SUB] = 3.47 ± 0.38 M[SUB]Jup[/SUB], a radius R[SUB]p[/SUB] = 1.31 ± 0.18 R[SUB]Jup[/SUB], and a density ρ[SUB]p[/SUB] = 2.2 ± 0.8 g cm[SUP]-3[/SUP]. It orbits a G9V star with a mass M[SUB]⋆[/SUB] = 0.95 ± 0.15 M[SUB]&sun;[/SUB], a radius R[SUB]⋆[/SUB] = 1.00 ± 0.13 R[SUB]&sun;[/SUB], and arotation period P[SUB]rot[/SUB] = 5.4 ± 0.4 days. The age of the system remains uncertain, with stellar evolution models pointing either to a few tens Ma or several Ga, while gyrochronology and lithium abundance point towards ages of a few hundred Ma. This mismatch potentially points to a problem in our understanding of the evolution of young stars, with possibly significant implications for stellar physics and the interpretation of inferred sizes of exoplanets around young stars. We detected the Rossiter-McLaughlin anomaly in the CoRoT-18 system thanks to the spectroscopic observation of a transit. We measured the obliquity ψ = 20° ± 20° (sky-projected value λ = -10° ± 20°), indicating that the planet orbits in the same way as the star is rotating and that this prograde orbit is nearly aligned with the stellar equator. The CoRoT space mission, launched on 2006 December 27, has been developed and is operated by CNES, with the contribution of Austria, Belgium, Brazil, ESA (RSSD and Science Programme), Germany and Spain.Table 2 is available in electronic form at <A href="http://www.aanda.org">http://www.aanda.org</A> [less ▲]

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See detailTRAPPIST: TRAnsiting Planets and PlanetesImals Small Telescope
Jehin, Emmanuel ULg; Gillon, Michaël ULg; Queloz, D. et al

in The Messenger (2011), 145

TRAPPIST is a 60-cm robotic telescope that was installed in April 2010 at the ESO La Silla Observatory. The project is led by the Astrophysics and Image Processing group (AIP) at the Department of ... [more ▼]

TRAPPIST is a 60-cm robotic telescope that was installed in April 2010 at the ESO La Silla Observatory. The project is led by the Astrophysics and Image Processing group (AIP) at the Department of Astrophysics, Geophysics and Oceanography (AGO) of the University of Liège, in close collaboration with the Geneva Observatory, and has been funded by the Belgian Fund for Scientific Research (F.R.S.-FNRS) and the Swiss National Science Foundation (SNF). It is devoted to the detection and characterisation of exoplanets and to the study of comets and other small bodies in the Solar System. We describe here the goals of the project and the hardware and present some results obtained during the first six months of operation. [less ▲]

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See detailWASP-31b: a low-density planet transiting a metal-poor, late-F-type dwarf star
Anderson, D. R.; Collier Cameron, A.; Hellier, C. et al

in Astronomy and Astrophysics (2011), 531

We report the discovery of the low-density, transiting giant planet WASP-31b. The planet is 0.47 Jupiter masses and 1.56 Jupiter radii. It is in a 3.4-day orbit around a 1-Gyr-old, late-F-type, V = 11.7 ... [more ▼]

We report the discovery of the low-density, transiting giant planet WASP-31b. The planet is 0.47 Jupiter masses and 1.56 Jupiter radii. It is in a 3.4-day orbit around a 1-Gyr-old, late-F-type, V = 11.7 star, which is a member of a common proper motion pair. In terms of its low density, WASP-31b is second only to WASP-17b, which is a more highly irradiated planet of similar mass. [less ▲]

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See detailWASP-23b: a transiting hot Jupiter around a K dwarf and its Rossiter-McLaughlin effect
Triaud, A H M J; Queloz, D.; Hellier, C. et al

in Astronomy and Astrophysics (2011), 531

We report the discovery of a new transiting planet in the southern hemisphere. It was found by the WASP-south transit survey and confirmed photometrically and spectroscopically by the 1.2 m Swiss Euler ... [more ▼]

We report the discovery of a new transiting planet in the southern hemisphere. It was found by the WASP-south transit survey and confirmed photometrically and spectroscopically by the 1.2 m Swiss Euler telescope, LCOGT 2m Faulkes South Telescope, the 60 cm TRAPPIST telescope, and the ESO 3.6 m telescope. The orbital period of the planet is 2.94 days. We find that it is a gas giant with a mass of 0.88 ± 0.10 M[SUB]J[/SUB] and an estimated radius of 0.96 ± 0.05 R[SUB]J[/SUB]. We obtained spectra during transit with the HARPS spectrograph and detect the Rossiter-McLaughlin effect despite its small amplitude. Because of the low signal-to-noise ratio of the effect and a small impact parameter, we cannot place a strong constraint on the projected spin-orbit angle. We find two conflicting values for the stellar rotation. We find, via spectral line broadening, that v sin I = 2.2 ± 0.3 km s[SUP]-1[/SUP], while applying another method, based on the activity level using the index log R'_HK, gives an equatorial rotation velocity of only v = 1.35 ± 0.20 km s[SUP]-1[/SUP]. Using these as priors in our analysis, the planet might be either misaligned or aligned. This result raises doubts about the use of such priors. There is evidence of neither eccentricity nor any radial velocity drift with time. Using WASP-South photometric observations confirmed with LCOGT Faulkes South Telescope, the 60 cm TRAPPIST telescope, the CORALIE spectrograph and the camera from the Swiss 1.2 m Euler Telescope placed at La Silla, Chile, as well as with the HARPS spectrograph, mounted on the ESO 3.6 m, also at La Silla, under proposal 084.C-0185. The data is publicly available at the CDS Strasbourg and on demand to the main author.RV data is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via <A href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/531/A24">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/531/A24</A>Appendix is available in electronic form at <A href="http://www.aanda.org">http://www.aanda.org</A> [less ▲]

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See detailTransiting exoplanets from the CoRoT space mission. XVII. The hot Jupiter CoRoT-17b: a very old planet
Csizmadia, Szilard; Moutou, C.; Deleuil, M. et al

in Astronomy and Astrophysics (2011), 531

We report on the discovery of a hot Jupiter-type exoplanet, CoRoT-17b, detected by the CoRoT satellite. It has a mass of 2.43 ± 0.30 M[SUB]Jup[/SUB] and a radius of 1.02 ± 0.07 R[SUB]Jup[/SUB], while its ... [more ▼]

We report on the discovery of a hot Jupiter-type exoplanet, CoRoT-17b, detected by the CoRoT satellite. It has a mass of 2.43 ± 0.30 M[SUB]Jup[/SUB] and a radius of 1.02 ± 0.07 R[SUB]Jup[/SUB], while its mean density is 2.82 ± 0.38 g/cm[SUP]3[/SUP]. CoRoT-17b is in a circular orbit with a period of 3.7681 ± 0.0003 days. The host star is an old (10.7 ± 1.0 Gyr) main-sequence star, which makes it an intriguing object for planetary evolution studies. The planet's internal composition is not well constrained and can range from pure H/He to one that can contain ~380 earth masses of heavier elements. 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. Part of the observations were obtained at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii. Based on observations made with HARPS spectrograph on the 3.6-m European Organisation for Astronomical Research in the Southern Hemisphere telescope at La Silla Observatory, Chile (ESO program 184.C-0639). Based on observations made with the IAC80 telescope operated on the island of Tenerife by the Instituto de Astrofísica de Canarias in the Spanish Observatorio del Teide. Part of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation. [less ▲]

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See detailThe spin-orbit angles of the transiting exoplanets WASP-1b, WASP-24b, WASP-38b and HAT-P-8b from Rossiter-McLaughlin observations
Simpson, E. K.; Pollacco, D.; Collier Cameron, A. et al

in Monthly Notices of the Royal Astronomical Society (2011), 414

We present observations of the Rossiter-McLaughlin effect for the transiting exoplanet systems WASP-1, WASP-24, WASP-38 and HAT-P-8, and deduce the orientations of the planetary orbits with respect to the ... [more ▼]

We present observations of the Rossiter-McLaughlin effect for the transiting exoplanet systems WASP-1, WASP-24, WASP-38 and HAT-P-8, and deduce the orientations of the planetary orbits with respect to the host stars' rotation axes. The planets WASP-24b, WASP-38b and HAT-P-8b appear to move in prograde orbits and be well aligned, having sky-projected spin orbit angles consistent with zero: {\lambda} = -4.7 \pm 4.0{\deg}, {\lambda} = 15 + 33{\deg}/-43{\deg} and {\lambda} = -9.7 +9.0{\deg}/-7.7{\deg}, respectively. The host stars have Teff < 6250 K and conform with the trend of cooler stars having low obliquities. WASP-38b is a massive planet on a moderately long period, eccentric orbit so may be expected to have a misaligned orbit given the high obliquities measured in similar systems. However, we find no evidence for a large spin-orbit angle. By contrast, WASP-1b joins the growing number of misaligned systems and has an almost polar orbit, {\lambda} = -79 +4.5{\deg}/-4.3{\deg}. It is neither very massive, eccentric nor orbiting a hot host star, and therefore does not share the properties of many other misaligned systems. [less ▲]

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See detailSpin-orbit measurements and refined parameters for the exoplanet systems WASP-22 and WASP-26
Anderson, D. R.; Collier Cameron, A.; Gillon, Michaël ULg et al

in Astronomy and Astrophysics (2011), 534

We report on spectroscopic and photometric observations through transits of the exoplanets WASP-22b and WASP-26b, intended to determine the systems' spin-orbit angles. We combine these data with existing ... [more ▼]

We report on spectroscopic and photometric observations through transits of the exoplanets WASP-22b and WASP-26b, intended to determine the systems' spin-orbit angles. We combine these data with existing data to refine the system parameters. We measure a sky-projected spin-orbit angle of 22 ± 16° for WASP-22b, showing the planet's orbit to be prograde and, perhaps, slightly misaligned. We do not detect the Rossiter-McLaughlin effect of WASP-26b due to its low amplitude and observation noise. We place 3-σ upper limits on orbital eccentricity of 0.063 for WASP-22b and 0.050 for WASP-26b. After refining the drift in the systemic velocity of WASP-22 found by Maxted et al. (2010, AJ, 140, 2007), we find the third body in the system to have a minimum-mass of 5.3 ± 0.3 MJup (a3 / 5 AU)2, where a3 is the orbital distance of the third body. [less ▲]

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See detailWASP-40b: Independent Discovery of the 0.6 M Transiting Exoplanet HAT-P-27b
Anderson, D. R.; Barros, S. C. C.; Boisse, I. et al

in Publications of the Astronomical Society of the Pacific [=PASP] (2011), 123

From WASP photometry and SOPHIE radial velocities we report the discovery of WASP-40b (HAT-P-27b), a 0.6 M planet that transits its 12th magnitude host star every 3.04 days. The host star is of late G ... [more ▼]

From WASP photometry and SOPHIE radial velocities we report the discovery of WASP-40b (HAT-P-27b), a 0.6 M planet that transits its 12th magnitude host star every 3.04 days. The host star is of late G-type or early K-type and likely has a metallicity greater than solar ([Fe/H]=0.14±0.11). The planet's mass and radius are typical of the known hot Jupiters, thus adding another system to the apparent pileup of transiting planets with periods near 3-4 days. Our parameters match those of the recent HATnet announcement of the same planet, thus giving confidence in the techniques used. We report a possible indication of stellar activity in the host star. [less ▲]

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See detailWASP-41b: A transiting hot Jupiter planet orbiting a magnetically-active G8V star
Maxted, P. F. L.; Anderson, D. R.; Collier Cameron, A. et al

in Publications of the Astronomical Society of the Pacific [=PASP] (2011), 123

We report the discovery of a transiting planet with an orbital period of 3.05d orbiting the star TYC 7247-587-1. The star, WASP-41, is a moderately bright G8V star (V=11.6) with a metallicity close to ... [more ▼]

We report the discovery of a transiting planet with an orbital period of 3.05d orbiting the star TYC 7247-587-1. The star, WASP-41, is a moderately bright G8V star (V=11.6) with a metallicity close to solar ([Fe/H]=-0.08+-0.09). The star shows evidence of moderate chromospheric activity, both from emission in the cores of the CaII H and K lines and photometric variability with a period of 18.3d and an amplitude of about 1%. The rotation period of the star implies a gyrochronological age for WASP-41 of 1.8Gyr with an error of about 15%. We have used a combined analysis of the available photometric and spectroscopic data to derive the mass and radius of the planet (0.93+-0.06M_Jup, 1.21+-0.06R_Jup). Further observations of WASP-41 can be used to explore the connections between the properties of hot Jupiter planets and the level of chromospheric activity in their host stars. [less ▲]

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See detailTransiting exoplanets from the CoRoT space mission. XVI. CoRoT-14b: an unusually dense very hot Jupiter
Tingley, B.; Endl, M.; Gazzano, J*-C et al

in Astronomy and Astrophysics (2011), 528

In this paper, the CoRoT ExoplanetScience Team announces its 14th discovery. Herein, we discuss the observations and analyses that allowed us to derive the parameters of this system: a hot Jupiter with a ... [more ▼]

In this paper, the CoRoT ExoplanetScience Team announces its 14th discovery. Herein, we discuss the observations and analyses that allowed us to derive the parameters of this system: a hot Jupiter with a mass of 7.6 ± 0.6 Jupiter masses orbiting a solar-type star (F9V) with a period of only 1.5 d, less than 5 stellar radii from its parent star. It is unusual for such a massive planet to have such a small orbit: only one other known higher mass exoplanet orbits with a shorter period. The CoRoT space mission, launched on December 27, 2006, has been developed and is operated by the CNES, with the contribution of Austria, Belgium, Brazil, ESA (RSSD and Science Program), Germany and Spain. [less ▲]

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See detailTRAPPIST: a robotic telescope dedicated to the study of planetary systems
Gillon, Michaël ULg; Jehin, Emmanuel ULg; Magain, Pierre ULg et al

in EPJ Web of Conferences (2011, February 01), 11

We present here a new robotic telescope called TRAPPIST<xref ref-type="fn" rid="FN2">1</xref> (TRAnsiting Planets and PlanetesImals Small Telescope). Equipped with a high-quality CCD camera mounted on a 0 ... [more ▼]

We present here a new robotic telescope called TRAPPIST<xref ref-type="fn" rid="FN2">1</xref> (TRAnsiting Planets and PlanetesImals Small Telescope). Equipped with a high-quality CCD camera mounted on a 0.6 meter light weight optical tube, TRAPPIST has been installed in April 2010 at the ESO La Silla Observatory (Chile), and is now beginning its scientific program. The science goal of TRAPPIST is the study of planetary systems through two approaches: the detection and study of exoplanets, and the study of comets. We describe here the objectives of the project, the hardware, and we present some of the first results obtained during the commissioning phase. [less ▲]

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See detailThe WASP-South search for transiting exoplanets
Hellier, C.; Anderson, D. R.; Collier Cameron, A. et al

in EPJ Web of Conferences (2011, February 01), 11

Since 2006 WASP-South has been scanning the Southern sky for transiting exoplanets. Combined with Geneva Observatory radial velocities we have so far found over 30 transiting exoplanets around relatively ... [more ▼]

Since 2006 WASP-South has been scanning the Southern sky for transiting exoplanets. Combined with Geneva Observatory radial velocities we have so far found over 30 transiting exoplanets around relatively bright stars of magnitude 9-13. We present a status report for this ongoing survey. [less ▲]

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See detailWASP-34b: a near-grazing transiting sub-Jupiter-mass exoplanet in a hierarchical triple system
Smalley, B.; Anderson, D. R.; Collier Cameron, A. et al

in Astronomy and Astrophysics (2011), 526

We report the discovery of WASP-34b, a sub-Jupiter-mass exoplanet transiting its 10.4-magnitude solar-type host star (1SWASP J110135.89-235138.4; TYC 6636-540-1) every 4.3177 days in a slightly eccentric ... [more ▼]

We report the discovery of WASP-34b, a sub-Jupiter-mass exoplanet transiting its 10.4-magnitude solar-type host star (1SWASP J110135.89-235138.4; TYC 6636-540-1) every 4.3177 days in a slightly eccentric orbit (e = 0.038 +/- 0.012). We find a planetary mass of 0.59 +/- 0.01 M_Jup and radius of 1.22 ^{+0.11}_{-0.08} R_Jup. There is a linear trend in the radial velocities of 55+/-4 m/s/y indicating the presence of a long-period third body in the system with a mass > 0.45 M_Jup at a distance of >1.2 AU from the host star. This third-body is either a low-mass star, white dwarf, or another planet. The transit depth ((R_P/R_*)^2 = 0.0126) and high impact parameter (b = 0.90) suggest that this could be the first known transiting exoplanet expected to undergo grazing transits, but with a confidence of only ~80%. [less ▲]

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See detailTransiting exoplanets from the CoRoT space mission. XV. CoRoT-15b: a brown-dwarf transiting companion
Bouchy, F.; Deleuil, M.; Guillot, T. et al

in Astronomy and Astrophysics (2011), 525

We report the discovery by the CoRoT space mission of a transiting brown dwarf orbiting a F7V star with an orbital period of 3.06 days. CoRoT-15b has a radius of 1.12[SUP]+0.30[/SUP][SUB]-0.15[/SUB] {R ... [more ▼]

We report the discovery by the CoRoT space mission of a transiting brown dwarf orbiting a F7V star with an orbital period of 3.06 days. CoRoT-15b has a radius of 1.12[SUP]+0.30[/SUP][SUB]-0.15[/SUB] {R}_Jup and a mass of 63.3 ± 4.1 {M}_Jup, and is thus the second transiting companion lying in the theoretical mass domain of brown dwarfs. CoRoT-15b is either very young or inflated compared to standard evolution models, a situation similar to that of M-dwarf stars orbiting close to solar-type stars. Spectroscopic constraints and an analysis of the lightcurve imply a spin period in the range 2.9-3.1 days for the central star, which is compatible with a double-synchronisation of the system. 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. Observations made with HARPS spectrograph at ESO La Silla Observatory (184.C-0639). [less ▲]

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See detailWASP-25b: a 0.6 M-J planet in the Southern hemisphere
Enoch, B.; Cameron, A Collier; Anderson, D. R. et al

in Monthly Notices of the Royal Astronomical Society (2011), 410(3), 16311636

We report the detection of a 0.6 M-J extrasolar planet by WASP-South, WASP-25b, transiting its solar-type host star every 3.76d. A simultaneous analysis of the WASP, FTS and Euler photometry and CORALIE ... [more ▼]

We report the detection of a 0.6 M-J extrasolar planet by WASP-South, WASP-25b, transiting its solar-type host star every 3.76d. A simultaneous analysis of the WASP, FTS and Euler photometry and CORALIE spectroscopy yields a planet of R[SUB]p[/SUB] = 1.22 R[SUB]J[/SUB] and M[SUB]p[/SUB] = 0.58 M[SUB]J[/SUB] around a slightly metal-poor solar-type host star, [Fe/H] = - 0.05 +/- 0.10, of R[SUB]*[/SUB] = 0.92 R[SUB]solar[/SUB] and M[SUB]*[/SUB] = 1.00 M[SUB]solar[/SUB]. WASP-25b is found to have a density of ρ[SUB]p[/SUB] = 0.32 ρ[SUB]J[/SUB], a low value for a sub-Jupiter mass planet. We investigate the relationship of planetary radius to planetary equilibrium temperature and host star metallicity for transiting exoplanets with a similar mass to WASP-25b, finding that these two parameters explain the radii of most low-mass planets well. [less ▲]

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See detailWASP-30b: a 61 Mjup brown dwarf transiting a V=12, F8 star
Anderson, D. R.; Collier Cameron, A.; Hellier, C. et al

in Astrophysical Journal Letters (2011), 726(2), 19

We report the discovery of a 61-Jupiter-mass brown dwarf (BD), which transits its F8V host star, WASP-30, every 4.16 days. From a range of age indicators we estimate the system age to be 1-2 Gyr. We ... [more ▼]

We report the discovery of a 61-Jupiter-mass brown dwarf (BD), which transits its F8V host star, WASP-30, every 4.16 days. From a range of age indicators we estimate the system age to be 1-2 Gyr. We derive a radius (0.89 ± 0.02 R Jup) for the companion that is consistent with that predicted (0.914 R Jup) by a model of a 1 Gyr old, non-irradiated BD with a dusty atmosphere. The location of WASP-30b in the minimum of the mass-radius relation is consistent with the quantitative prediction of Chabrier & Baraffe, thus confirming the theory. [less ▲]

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See detailWASP-22 b: A Transiting "Hot Jupiter" Planet in a Hierarchical Triple System
Maxted, P. F. L.; Anderson, D. R.; Gillon, Michaël ULg et al

in Astrophysical Journal (2010), 140(6), 2007-2012

We report the discovery of a transiting planet orbiting the star TYC 6446-326-1. The star, WASP-22, is a moderately bright (V = 12.0) solar-type star (T[SUB]eff[/SUB] = 6000 ± 100 K, [Fe/H] = –0.05 ± 0.08 ... [more ▼]

We report the discovery of a transiting planet orbiting the star TYC 6446-326-1. The star, WASP-22, is a moderately bright (V = 12.0) solar-type star (T[SUB]eff[/SUB] = 6000 ± 100 K, [Fe/H] = –0.05 ± 0.08). The light curve of the star obtained with the WASP-South instrument shows periodic transit-like features with a depth of about 1% and a duration of 0.14 days. The presence of a transit-like feature in the light curve is confirmed using z-band photometry obtained with Faulkes Telescope South. High-resolution spectroscopy obtained with the CORALIE and HARPS spectrographs confirms the presence of a planetary mass companion with an orbital period of 3.533 days in a near-circular orbit. From a combined analysis of the spectroscopic and photometric data assuming that the star is a typical main-sequence star we estimate that the planet has a mass M [SUB]p[/SUB] = 0.56 ± 0.02M [SUB]Jup[/SUB] and a radius R [SUB]p[/SUB] = 1.12 ± 0.04R [SUB]Jup[/SUB]. In addition, there is a linear trend of 40 m s[SUP]–1[/SUP] yr[SUP]–1[/SUP] in the radial velocities measured over 16 months, from which we infer the presence of a third body with a long-period orbit in this system. The companion may be a low mass M-dwarf, a white dwarf, or a second planet. [less ▲]

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See detailSpin-orbit angle measurements for six southern transiting planets. New insights into the dynamical origins of hot Jupiters
Triaud, A H M J; Collier Cameron, A.; Queloz, D. et al

in Astronomy and Astrophysics (2010), 524

Context. Several competing scenarios for planetary-system formation and evolution seek to explain how hot Jupiters came to be so close to their parent stars. Most planetary parameters evolve with time ... [more ▼]

Context. Several competing scenarios for planetary-system formation and evolution seek to explain how hot Jupiters came to be so close to their parent stars. Most planetary parameters evolve with time, making it hard to distinguish between models. The obliquity of an orbit with respect to the stellar rotation axis is thought to be more stable than other parameters such as eccentricity. Most planets, to date, appear aligned with the stellar rotation axis; the few misaligned planets so far detected are massive (> 2 M[SUB]J[/SUB]). <BR /> Aims: Our goal is to measure the degree of alignment between planetary orbits and stellar spin axes, to search for potential correlations with eccentricity or other planetary parameters and to measure long term radial velocity variability indicating the presence of other bodies in the system. <BR /> Methods: For transiting planets, the Rossiter-McLaughlin effect allows the measurement of the sky-projected angle β between the stellar rotation axis and a planet's orbital axis. Using the HARPS spectrograph, we observed the Rossiter-McLaughlin effect for six transiting hot Jupiters found by the WASP consortium. We combine these with long term radial velocity measurements obtained with CORALIE. We used a combined analysis of photometry and radial velocities, fitting model parameters with the Markov Chain Monte Carlo method. After obtaining β we attempt to statistically determine the distribution of the real spin-orbit angle ψ. <BR /> Results: We found that three of our targets have β above 90°: WASP-2b: β = 153°[SUP]+11[/SUP][SUB]-15[/SUB], WASP-15b: β = 139.6°[SUP]+5.2[/SUP][SUB]-4.3[/SUB] and WASP-17b: β = 148.5°[SUP]+5.1[/SUP][SUB]-4.2[/SUB]; the other three (WASP-4b, WASP-5b and WASP-18b) have angles compatible with 0°. We find no dependence between the misaligned angle and planet mass nor with any other planetary parameter. All six orbits are close to circular, with only one firm detection of eccentricity e = 0.00848[SUP]+0.00085[/SUP][SUB]-0.00095[/SUB] in WASP-18b. No long-term radial acceleration was detected for any of the targets. Combining all previous 20 measurements of β and our six and transforming them into a distribution of ψ we find that between about 45 and 85% of hot Jupiters have ψ > 30°. <BR /> Conclusions: Most hot Jupiters are misaligned, with a large variety of spin-orbit angles. We find observations and predictions using the Kozai mechanism match well. If these observational facts are confirmed in the future, we may then conclude that most hot Jupiters are formed from a dynamical and tidal origin without the necessity to use type I or II migration. At present, standard disc migration cannot explain the observations without invoking at least another additional process. Using observations with the high resolution échelle spectrograph HARPS mounted on the ESO 3.6 m (under proposals 072.C-0488, 082.C-0040 & 283.C-5017), and with the high resolution échelle spectrograph CORALIE on the 1.2 m Euler Swiss Telescope, both installed at the ESO La Silla Observatory in Chile.RV data is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via <A href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/524/A25">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/524/A25</A> [less ▲]

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See detailExoplanet discoveries with the CoRoT space observatory
Lammer, H.; Dvorak, R.; Deleuil, M. et al

in Solar System Research (2010), 44

The CoRoT space observatory is a project which is led by the French space agency CNES and leading space research institutes in Austria, Brazil, Belgium, Germany and Spain and also the European Space ... [more ▼]

The CoRoT space observatory is a project which is led by the French space agency CNES and leading space research institutes in Austria, Brazil, Belgium, Germany and Spain and also the European Space Agency ESA. CoRoT observed since its launch in December 27, 2006 about 100 000 stars for the exoplanet channel, during 150 days uninterrupted high-precision photometry. Since the The CoRoT-team has several exoplanet candidates which are currently analyzed under its study, we report here the discoveries of nine exoplanets which were observed by CoRoT. Discovered exoplanets such as CoRoT-3b populate the brown dwarf desert and close the gap of measured physical properties between usual gas giants and very low mass stars. CoRoT discoveries extended the known range of planet masses down to about 4.8 Earth-masses (CoRoT-7b) and up to 21 Jupiter masses (CoRoT-3b), the radii to about 1.68 × 0.09 R [SUB]Earth[/SUB] (CoRoT-7b) and up to the most inflated hot Jupiter with 1.49 × 0.09 R [SUB]Earth[/SUB] found so far (CoRoT-1b), and the transiting exoplanet with the longest period of 95.274 days (CoRoT-9b). Giant exoplanets have been detected at low metallicity, rapidly rotating and active, spotted stars. Two CoRoT planets have host stars with the lowest content of heavy elements known to show a transit hinting towards a different planethost-star-metallicity relation then the one found by radial-velocity search programs. Finally the properties of the CoRoT-7b prove that rocky planets with a density close to Earth exist outside the Solar System. Finally the detection of the secondary transit of CoRoT-1b at a sensitivity level of 10[SUP]-5[/SUP] and the very clear detection of the "super-Earth" CoRoT-7b at 3.5 × 10[SUP]-4[/SUP] relative flux are promising evidence that the space observatory is being able to detect even smaller exoplanets with the size of the Earth. [less ▲]

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