The exceptional story of massive IIA supergravity

The framework of exceptional field theory is extended by introducing consistent deformations of its generalised Lie derivative. For the first time, massive type IIA supergravity is reproduced geometrically as a solution of the section constraint. This provides a unified description of all ten- and eleven-dimensional maximal supergravities. The action of the E7 deformed theory is constructed, and reduces to those of exceptional field theory and gauged maximal supergravity in respective limits. The relation of this new framework to other approaches for generating the Romans mass non-geometrically is discussed.Comment: 39 pages. v2: typos corrected, references added. v3: typos corrected, references added, published versio

IIB Supergravity and the E6(6) covariant vector-tensor hierarchy

IIB supergravity is reformulated with a manifest local USp(8) invariance that makes the embedding of five-dimensional maximal supergravities transparent. In this formulation the ten-dimensional theory exhibits all the 27 one-form fields and 22 of the 27 two-form fields that are required by the vector-tensor hierarchy of the five-dimensional theory. The missing 5 two-form fields must transform in the same representation as a descendant of the ten-dimensional `dual graviton'. The invariant E6(6) symmetric tensor that appears in the vector-tensor hierarchy is reproduced. Generalized vielbeine are derived from the supersymmetry transformations of the vector fields, as well as consistent expressions for the USp(8) covariant fermion fields. Implications are discussed for the consistency of the truncation of IIB supergravity compactified on the five-sphere to maximal gauged supergravity in five space-time dimensions with an SO(6) gauge group.Comment: 48 pages, added an extra affiliatio

Kepler-447b: a hot-Jupiter with an extremely grazing transit

We present the radial velocity confirmation of the extrasolar planet Kepler-447b, initially detected as a candidate by the Kepler mission. In this work, we analyze its transit signal and the radial velocity data obtained with the Calar Alto Fiber-fed Echelle spectrograph (CAFE). By simultaneously modeling both datasets, we obtain the orbital and physical properties of the system. According to our results, Kepler-447b is a Jupiter-mass planet ($M_p=1.37^{+0.48}_{-0.46}~M_{\rm Jup}$), with an estimated radius of $R_p=1.65^{+0.59}_{-0.56}~R_{\rm Jup}$ (uncertainties provided in this work are $3\sigma$ unless specified). This translates into a sub-Jupiter density. The planet revolves every $\sim7.8$ days in a slightly eccentric orbit ($e=0.123^{+0.037}_{-0.036}$) around a G8V star with detected activity in the Kepler light curve. Kepler-447b transits its host with a large impact parameter ($b=1.076^{+0.112}_{-0.086}$), being one of the few planetary grazing transits confirmed so far and the first in the Kepler large crop of exoplanets. We estimate that only around 20% of the projected planet disk occults the stellar disk. The relatively large uncertainties in the planet radius are due to the large impact parameter and short duration of the transit. Planets with such an extremely large impact parameter can be used to detect and analyze interesting configurations such as additional perturbing bodies, stellar pulsations, rotation of a non-spherical planet, or polar spot-crossing events. All these scenarios would periodically modify the transit properties (depth, duration, and time of mid-transit), what could be detectable with sufficient accurate photometry. Short-cadence photometric data (at the 1 minute level) would help in the search for these exotic configurations in grazing planetary transits like that of Kepler-447b.Comment: Accepted for publication in A&A. 13 pages, 8 figures, 4 tables. This version replaces an earlier version of the pape

Kepler-539: a young extrasolar system with two giant planets on wide orbits and in gravitational interaction

We confirm the planetary nature of Kepler-539b (aka Kepler object of interest K00372.01), a giant transiting exoplanet orbiting a solar-analogue G2 V star. The mass of Kepler-539b was accurately derived thanks to a series of precise radial velocity measurements obtained with the CAFE spectrograph mounted on the CAHA 2.2m telescope. A simultaneous fit of the radial-velocity data and Kepler photometry revealed that Kepler-539b is a dense Jupiter-like planet with a mass of Mp = 0.97 Mjup and a radius of Rp = 0.747 Rjup, making a complete circular revolution around its parent star in 125.6 days. The semi-major axis of the orbit is roughly 0.5 au, implying that the planet is at roughly 0.45 au from the habitable zone. By analysing the mid-transit times of the 12 transit events of Kepler-539b recorded by the Kepler spacecraft, we found a clear modulated transit time variation (TTV), which is attributable to the presence of a planet c in a wider orbit. The few timings available do not allow us to precisely estimate the properties of Kepler-539c and our analysis suggests that it has a mass between 1.2 and 3.6 Mjup, revolving on a very eccentric orbit (0.4<e<0.6) with a period larger than 1000 days. The high eccentricity of planet c is the probable cause of the TTV modulation of planet b. The analysis of the CAFE spectra revealed a relatively high photospheric lithium content, A(Li)=2.48 dex, which, together with both a gyrochronological and isochronal analysis, suggests that the parent star is relatively young.Comment: 11 pages, 14 figures, accepted for publication in Astronomy & Astrophysic

Physical properties, starspot activity, orbital obliquity, and transmission spectrum of the Qatar-2 planetary system from multi-colour photometry

We present seventeen high-precision light curves of five transits of the planet Qatar-2b, obtained from four defocussed 2m-class telescopes. Three of the transits were observed simultaneously in the SDSS griz passbands using the seven-beam GROND imager on the MPG/ESO 2.2-m telescope. A fourth was observed simultaneously in Gunn grz using the CAHA 2.2-m telescope with BUSCA, and in r using the Cassini 1.52-m telescope. Every light curve shows small anomalies due to the passage of the planetary shadow over a cool spot on the surface of the host star. We fit the light curves with the prism+gemc model to obtain the photometric parameters of the system and the position, size and contrast of each spot. We use these photometric parameters and published spectroscopic measurements to obtain the physical properties of the system to high precision, finding a larger radius and lower density for both star and planet than previously thought. By tracking the change in position of one starspot between two transit observations we measure the orbital obliquity of Qatar-2 b to be 4.3 \pm 4.5 degree, strongly indicating an alignment of the stellar spin with the orbit of the planet. We calculate the rotation period and velocity of the cool host star to be 11.4 \pm 0.5 d and 3.28 \pm 0.13 km/s at a colatitude of 74 degree. We assemble the planet's transmission spectrum over the 386-976 nm wavelength range and search for variations of the measured radius of Qatar-2 b as a function of wavelength. Our analysis highlights a possible H2/He Rayleigh scattering in the blue.Comment: 20 pages, 14 figures, to appear in Monthly Notices of the Royal Astronomical Societ

La prise en compte de la diversité culturelle et religieuse dans les normes et pratiques de gestion des établissements scolaires : une étude exploratoire dans cinq provinces canadiennes

Les autrices présentent quelques résultats d'une vaste enquête à caractère exploratoire menée, en 1994-1995, auprès de répondants clés des ministères de l'Education et des autorités scolaires locales, sur la prise en compte de la diversité culturelle et religieuse dans les normes et les pratiques de gestion des établissements scolaires de cinq provinces canadiennes (Colombie-Britannique, Alberta, Ontario, Québec, Nouvelle-Ecosse). De manière générale, une ouverture appré- ciable à la diversité semble exister dans l'ensemble des milieux. En guise de conclusion, les autrices dégagent l'apport potentiel des recherches de terrain aux réflexions de nature plus théorique qui se développent actuellement sur l'éducation à la citoyen- neté et la formation de ceux et celles qui auront à en assurer l'actualisation en milieu scolaire.The authors present some of the results of an exploratory large-scale survey, conducted in 1994-1995, of representatives of the Ministers of Education and local school authorities, describing how cultural and religions diversity are considered in administrative norms and practices of schools in five Canadian provinces (British Columbia, Alberta, Ontario, Quebec, and Nova Scotia). Generally, the findings show that there is a notable presence of these considerations in all these cases. Among the conclusions, the authors point out the impor- tance of empirical research to further theoretical discussions regarding citizenship education and the importance of training of those with the task of implementing these programmes in schools.Las autoras presentan algunos resultados de una vasta encuesta exploratoria realizada en 1994-95 sobre la forma en que se consideran la diversidad cultural y religiosa en las normas y practicas de gestion de los establecimientos escolares en cinco provincias canadienses (Colombia Britânica, Alberta, Ontario, Quebec y Nueva Escocia); fueron encues- tadas personas clave en ministerios de Educacion y autoridades escolares locales. De manera general, parece existir una apertura apreciable en el conjunto de estos medios. En conclu- sion, las autoras identifican el aporte potencial de las investigaciones sobre el terreno para la reflexion de naturaleza teorica, actualmente en desarrollo, sobre la educacion sobre la ciudadania y la formacion de aquéllos que tendran que responsabilizarse de su realization en el medio escolar.Die Verfasserinnen stellen hier die Ergebnisse einer umfassenden Umfrage vor, die sie 1994-95 unter ausgewâhlten Personnen der Erziehungsministerien und Schuldirek- tionen unternommen haben mit dem Ziel, herauszufinden, inwieweit die kulturelle und religiose Vielfalt innerhalb der Normen und der Verwaltungspraktiken der Schulen in fûnf kanadischen Provinzen (British-Columbia, Alberta, Ontario, Québec, Nova-Scotia) berucksichtigt wird. Dieser Vielfalt steht man iiberall ziemlich aufgeschlossen gegenûber. Zum Schluss legen die Verfasserinnen dar, wie die praktischen Forschungsprojekte zu der Beantwortung der mehr theoretischen Fragen beitragen kônnen, die heutzutage im Zusammenhang mit der Bildung des Biïrgerbewufêtseins und mit der Ausbildung derer, die dièse Bildung in den Schulen in Tat umzusetzen haben werden, gestellt werden

Physical properties of the WASP-44 planetary system from simultaneous multi-colour photometry

We present ground-based broad-band photometry of two transits in the WASP-44 planetary system obtained simultaneously through four optical (Sloan g', r', i', z') and three near-infrared (NIR; J, H, K) filters. We achieved low scatters of 1-2 mmag per observation in the optical bands with a cadence of 48 s, but the NIR-band light curves present much greater scatter. We also observed another transit of WASP-44 b by using a Gunn-r filter and telescope defocussing, with a scatter of 0.37 mmag per point and an observing cadence around 135 s. We used these data to improve measurements of the time of mid-transit and the physical properties of the system. In particular, we improved the radius measurements of the star and planet by factors of 3 and 4, respectively. We find that the radius of WASP-44 b is 1.002 R_Jup, which is slightly smaller than previously thought and differs from that expected for a core-free planet. In addition, with the help of a synthetic spectrum, we investigated the theoretically-predicted variation of the planetary radius as a function of wavelength, covering the range 370-2440 nm. We can rule out extreme variations at optical wavelengths, but unfortunately our data are not precise enough (especially in the NIR bands) to differentiate between the theoretical spectrum and a radius which does not change with wavelength.Comment: 13 pages, 6 figures, to appear in Monthly Notices of the Royal Astronomical Societ

HATS-15b and HATS-16b: Two Massive Planets Transiting Old G Dwarf Stars

We report the discovery of HATS-15 b and HATS-16 b, two massive transiting extrasolar planets orbiting evolved (~10 Gyr) main-sequence stars. The planet HATS-15 b, which is hosted by a G9 V star (V = 14.8 mag), is a hot Jupiter with mass of 2.17 ± 0.15 M_J and radius of 1.105 ± 0.040 R_J, and it completes its orbit in about 1.7 days. HATS-16 b is a very massive hot Jupiter with mass of 3.27 ± 0.19 M_J and radius of 1.30 ± 0.15 R_J; it orbits around its G3 V parent star (V = 13.8 mag) in ~2.7 days. HATS-16 is slightly active and shows a periodic photometric modulation, implying a rotational period of 12 days, which is unexpectedly short given its isochronal age. This fast rotation might be the result of the tidal interaction between the star and its planet