55625415
WASP-32b: A Transiting Hot Jupiter Planet Orbiting a Lithium-Poor, Solar-Type Star
ABSTRACT. We report the discovery of a transiting planet orbiting the star TYC 2-1155-1. The star, WASP-32, is a moderately bright (V = 11.3 V = 11.3 ) solar-type star (Teff = 6100 ± 100 K T eff = 6100 ± 100 K , [Fe/H] = -0.13 ± 0.10 [ Fe / H ] = - 0.13 ± 0.10 ). The light curve of the star obtained with the WASP-South and WASP-North instruments shows periodic transitlike features with a depth of about 1% and a duration of 0.10 day every 2.72 days. The presence of a transitlike feature in the light curve is confirmed using z z -band photometry obtained with Faulkes Telescope North. High-resolution spectroscopy obtained with the Coralie spectrograph confirms the presence of a planetary mass companion. 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 Mp M p of 3.60 ± 0.07 MJup 3.60 ± 0.07 M Jup and a radius Rp = 1.19 ± 0.06 RJup R p = 1.19 ± 0.06 R Jup . WASP-32 is one of a small gro...
197440547
Report by the ESA-ESO Working Group on Extra-Solar Planets
Various techniques are being used to search for extra-solar planetary signatures, including accurate measurement of radial velocity and positional (astrometric) displacements, gravitational microlensing, and photometric transits. Planned space experiments promise a considerable increase in the detections and statistical knowledge arising especially from transit and astrometric measurements over the years 2005-15, with some hundreds of terrestrial-type planets expected from transit measurements, and many thousands of Jupiter-mass planets expected from astrometric measurements. Beyond 2015, very ambitious space (Darwin/TPF) and ground (OWL) experiments are targeting direct detection of nearby Earth-mass planets in the habitable zone and the measurement of their spectral characteristics. Beyond these, `Life Finder' (aiming to produce confirmatory evidence of the presence of life) and `Earth Imager' (some massive interferometric array providing resolved images of a distant Earth) appear as distant visions. This report, to ESA and ESO, summarises the direction of exo-planet research that can be expected over the next 10 years or so, identifies the roles of the major facilities of the two organisations in the field, and concludes with some recommendations which may assist development of the field. The report has been compiled by the Working Group members and experts over the period June-December 2004.
7786007
WASP-23b: a transiting hot Jupiter around a K dwarf and its Rossiter-McLaughlin effect
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 MJ and an estimated radius of 0.96 ± 0.05RJ. 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. 3k m s −1 , while applying another method, based on the activity level using the index log R � , gives an equatorial rotation velocity of only v = 1.35 ± 0.20 km s −1 . 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.
53687206
WASP-64 b and WASP-72 b: two new transiting highly irradiated giant planets
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 )a nd 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 M� ,1 .058 ± 0.025 R� , 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 +0.059 −0.056 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 M� ,1 .98 ± 0.24 R� , Teff = 6250 ± 100 K). Despite its extreme irradiation (∼5.5 × 10 9 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.
15260611
Spectropolarimetric observations of the transiting planetary system of the K dwarf HD 189733
With a Jupiter-mass planet orbiting at a distance of only 0.031 AU, the active K2 dwarf HD 189733 is a potential candidate in which to study the magnetospheric interactions of a cool star with its recently-discovered close-orbiting giant planet. We decided to explore the strength and topology of the large-scale magnetosphere of HD 189733, as a future benchmark for quantitative studies for models of the star/planet magnetic interactions. To this end, we used ESPaDOnS, the new generation spectropolarimeter at the Canada-France-Hawaii 3.6m telescope, to look for Zeeman circular polarisation signatures in the line profiles of HD 189733 in 2006 June and August. Zeeman signatures in the line profiles of HD 189733 are clearly detected in all spectra, demonstrating that a field is indeed present at the surface of the star. The Zeeman signatures are not modulated with the planet's orbital period but apparently vary with the stellar rotation cycle. The reconstructed large-scale magnetic field, whose strength reaches a few tens of G, is significantly more complex than that of the Sun; it involves in particular a significant toroidal component and contributions from magnetic multipoles of order up to 5. The CaII H & K lines clearly feature core emission, whose intensity is apparently varying mostly with rotation phase. Our data suggest that the photosphere and magnetic field of HD 189733 are sheared by a significant amount of differential rotation. Our initial study confirms that HD 189733 is an optimal target for investigating activity enhancements induced by closely orbiting planets. More data are needed, densely covering both the orbital and rotation cycles, to investigate whether and how much the planet contributes to the overall activity level of HD 189733.
14923552
Detection and Characterization of Extrasolar Planets through Doppler Spectroscopy
Over 300 extrasolar planets have been found since 1992, showing that planetary systems are common and exhibit an outstanding variety of characteristics. As the number of detections grows and as models of planet formation progress to account for the existence of these new worlds, statistical studies and confrontations of observation with theory allow to progressively unravel the key processes underlying planet formation. In this chapter we review the dominant contribution of Doppler
 spectroscopy to the present discoveries and to our general understanding of
 planetary systems. We also emphasize the synergy of Doppler spectroscopy and transit photometry in characterizing the physical properties of
 transiting extrasolar planets. As we will see, Doppler spectroscopy has not reached its limits yet and it will undoubtly play a leading role in the detection and characterization of the first Earth-mass planets.
7071388
Nonperturbative versus perturbative effects in generalized parton distributions
Generalized parton distributions (GPDs) are studied at the hadronic (nonperturbative) scale within different assumptions based on a relativistic constituent quark model. In particular, by means of a meson-cloud model we investigate the role of nonperturbative antiquark degrees of freedom and the valence-quark contribution. A QCD evolution of the obtained GPDs is used to add perturbative effects and to investigate the GPDs' sensitivity to the nonperturbative ingredients of the calculation at larger (experimental) scale.
17088589
Analytic treatment of positronium spin splittings in light-front QED
We study the QED bound-state problem in a light-front Hamiltonian approach. Starting with a bare cutoff QED Hamiltonian H{sub B} with matrix elements between free states of drastically different energies removed, we perform a similarity transformation that removes the matrix elements between free states with energy differences between the bare cutoff {Lambda} and effective cutoff {lambda} ({lambda}{lt}{Lambda}). This generates effective interactions in the renormalized Hamiltonian H{sub R}. These effective interactions are derived to order {alpha} in this work, with {alpha}{lt}1. H{sub R} is renormalized by requiring it to satisfy coupling coherence. A nonrelativistic limit of the theory is taken, and the resulting Hamiltonian is studied using bound-state perturbation theory. The effective cutoff {lambda}{sup 2} is fixed, and the limit 0{l_arrow}m{sup 2}{alpha}{sup 2}{lt}{lambda}{sup 2}{lt}m{sup 2}{alpha}{r_arrow}{infinity} is taken. This upper bound on {lambda}{sup 2} places the effects of low-energy (energy transfer below {lambda}) emission in the effective interactions in the {vert_bar}e{bar e}{r_angle} sector. This lower bound on {lambda}{sup 2} ensures that the nonperturbative scale of interest is not removed by the similarity transformation. As an explicit example of the general formalism introduced, we show that the Hamiltonian renormalized to O({alpha}) reproduces the exact spectrum of spin splittings, with degeneracies dictated by rotationalmore » symmetry, for the ground state through O({alpha}{sup 4}). The entire calculation is performed analytically, and gives the well-known singlet-triplet ground-state spin splitting of positronium, (7)/(6){alpha}{sup 2}Ryd. We discuss the remaining corrections other than the spin splittings and how they can be treated in calculating the spectrum with higher precision. {copyright} {ital 1997} {ital The American Physical Society}« less
18942639
Femtoscopically Probing the Freeze-out Configuration in Heavy Ion Collisions
Two-particle femtoscopy reveals the space-time substructure of the freeze-out configuration from heavy ion collisions. Detailed fingerprints of bulk collectivity are evident in space-momentum correlations, which have been systematically measured as a function of particle type, three-momentum, and collision conditions. A clear scenario, dominated by hydrodynamic-type flow emerges. Reproducing the strength and features of the femtoscopic signals in models involves important physical quantities like the Equation of State, as well as less fundamental technical details. An interesting approximate "factorization" in the measured systematics suggests that the overall physical freeze-out scale is set by final state chemistry, but the kinematic substructure is largely universal. Referring to previous results from hadron and lepton collisions, we point to the importance of determining whether these "universal" trends persist from the largest to the smallest systems. We review theoretical expectations for heavy ion femtoscopy at the LHC, and point to directions needing further theory and experimental work at RHIC and the LHC.