Using Kepler transit observations to measure stellar spot belt migration rates

Planetary transits provide a unique opportunity to investigate the surface distributions of star spots. Our aim is to determine if, with continuous observation (such as the data that will be provided by the Kepler mission), we can in addition measure the rate of drift of the spot belts. We begin by simulating magnetic cycles suitable for the Sun and more active stars, incorporating both flux emergence and surface transport. This provides the radial magnetic field distribution on the stellar surface as a function of time. We then model the transit of a planet whose orbital axis is misaligned with the stellar rotation axis. Such a planet could occult spots at a range of latitudes. This allows us to complete the forward modelling of the shape of the transit lightcurve. We then attempt the inverse problem of recovering spot locations from the transit alone. From this we determine if transit lightcurves can be used to measure spot belt locations as a function of time. We find that for low-activity stars such as the Sun, the 3.5 year Kepler window is insufficient to determine this drift rate. For more active stars, it may be difficult to distinguish subtle differences in the nature of flux emergence, such as the degree of overlap of the "butterfly wings". The rate and direction of drift of the spot belts can however be determined for these stars. This would provide a critical test of dynamo theory.Comment: 5 pages. Accepted for publication in Monthly Notices of the Royal Astronomical Society Letter

Metamorfosis del Contar. Semiosis/Memoria V. Massmediación: formatos y dispositivos. 16H344

Se explora la prensa gráfica en soporte papel y digital como complejo mnemosemiótico y comunicativo, para dar cuenta de la conformación y las características de este tipo de dispositivo performativo. Se indaga y analiza, con un enfoque interdisciplinar (Semiótica, Análisis del Discurso, Comunicación) y desde una perspectiva crítica y política, el diario en su totalidad y el trabajo de massmediación que lleva a cabo este tipo de textualidad compleja. Se pretende describir y caracterizar el formato, sus matrices semio-discursivas y comunicativas, y relevar y analizar los diversos géneros y discursos que lo conforman

Fundamental Properties of Kepler Planet-Candidate Host Stars using Asteroseismology

We have used asteroseismology to determine fundamental properties for 66 Kepler planet-candidate host stars, with typical uncertainties of 3% and 7% in radius and mass, respectively. The results include new asteroseismic solutions for four host stars with confirmed planets (Kepler-4, Kepler-14, Kepler-23 and Kepler-25) and increase the total number of Kepler host stars with asteroseismic solutions to 77. A comparison with stellar properties in the planet-candidate catalog by Batalha et al. shows that radii for subgiants and giants obtained from spectroscopic follow-up are systematically too low by up to a factor of 1.5, while the properties for unevolved stars are in good agreement. We furthermore apply asteroseismology to confirm that a large majority of cool main-sequence hosts are indeed dwarfs and not misclassified giants. Using the revised stellar properties, we recalculate the radii for 107 planet candidates in our sample, and comment on candidates for which the radii change from a previously giant-planet/brown-dwarf/stellar regime to a sub-Jupiter size, or vice versa. A comparison of stellar densities from asteroseismology with densities derived from transit models in Batalha et al. assuming circular orbits shows significant disagreement for more than half of the sample due to systematics in the modeled impact parameters, or due to planet candidates which may be in eccentric orbits. Finally, we investigate tentative correlations between host-star masses and planet candidate radii, orbital periods, and multiplicity, but caution that these results may be influenced by the small sample size and detection biases.Comment: 19 pages, 10 figures, 4 tables; accepted for publication in ApJ; machine-readable versions of tables 1-3 are available as ancillary files or in the source code; v2: minor changes to match published versio

Stellar Spin-Orbit Misalignment in a Multiplanet System

Stars hosting hot Jupiters are often observed to have high obliquities, whereas stars with multiple co-planar planets have been seen to have low obliquities. This has been interpreted as evidence that hot-Jupiter formation is linked to dynamical disruption, as opposed to planet migration through a protoplanetary disk. We used asteroseismology to measure a large obliquity for Kepler-56, a red giant star hosting two transiting co-planar planets. These observations show that spin-orbit misalignments are not confined to hot-Jupiter systems. Misalignments in a broader class of systems had been predicted as a consequence of torques from wide-orbiting companions, and indeed radial-velocity measurements revealed a third companion in a wide orbit in the Kepler-56 system.Comment: Accepted for publication in Science, published online on October 17 2013; PDF includes main article and supplementary materials (65 pages, 27 figures, 7 tables); v2: small correction to author lis

STARSPOTS AND SPIN-ORBIT ALIGNMENT IN THE WASP-4 EXOPLANETARY SYSTEM

We present photometry of four transits of the exoplanet WASP-4b, each with a precision of approximately 500 ppm and a time sampling of 40-60 s. We have used the data to refine the estimates of the system parameters and ephemerides. During two of the transits we observed a short-lived, low-amplitude anomaly that we interpret as the occultation of a starspot by the planet. We also found evidence for a pair of similar anomalies in previously published photometry. The recurrence of these anomalies suggests that the stellar rotation axis is nearly aligned with the orbital axis, or else the starspot would not have remained on the transit chord. By analyzing the timings of the anomalies we find the sky-projected stellar obliquity to be lambda = –1[superscrip +14 over subscript –12] degrees. This result is consistent with (and more constraining than) a recent observation of the Rossiter-McLaughlin effect. It suggests that the planet migration mechanism preserved the initially low obliquity, or else that tidal evolution has realigned the system. Future applications of this method using data from the CoRoT and Kepler missions will allow spin-orbit alignment to be probed for many other exoplanets.United States. National Aeronautics and Space Administration (NASA Origins program award NNX09AD36G)United States. National Aeronautics and Space Administration (NASA Origins program award NNX09AB33G)Massachusetts Institute of Technology (Class of 1942)Caja de Ahorros y Pensiones de BarcelonaSpace Telescope Science Institute (Hubble Fellowship grant HF-51267.01-A

Grid Poblacional 2011 para España

[ES] Este trabajo presenta una evaluación, desde el punto de vista del usuario, de la malla regular (grid) de población, con resolución de 1 km2, que el Instituto Nacional de Estadística (INE) ha hecho pública a partir de los resultados del Censo de Población y Viviendas 2011. Esta forma de difusión de resultados resulta muy novedosa y ofrece un gran valor analítico. Por primera vez esta información sobre la distribución espacial de la población se ha generado desde abajo (bottom-up) para el conjunto de España, es decir, a partir del conocimiento de las coordenadas de cada hogar, considerando como tales las del edificio donde reside. La disponibilidad de otra grid con idéntica resolución, elaborada por métodos de desagregación espacial a partir de la población censal por unidades administrativas e información auxiliar sobre coberturas del suelo (top-down), nos permite examinar las mejoras asociadas a la georreferenciación de la población acometida en el contexto de los cambios metodológicos del censo de 2011. De forma simultánea ello nos permite analizar las bondades de la grid censal.Goerlich-Gisbert, F.; Cantarino-Martí, I. (2017). Grid Poblacional 2011 para España. Estudios Geográficos. LXXVIII(282):135-163. doi:10.3989/estgeogr.201705S135163LXXVIII282Batista e Silva, F. (2011): "The effect of ancillary data in population dasymetric mapping: A test case using the original and a modified version of CORINE Land Cover", presentado en el European Forum for Geography and Statistics Conference (EFGS), Lisboa (Portugal), 12-14 de octubre de 2011.Batista e Silva, F., Lavalle, C., & Koomen, E. (2013). A procedure to obtain a refined European land use/cover map. Journal of Land Use Science, 8(3), 255-283. doi:10.1080/1747423x.2012.667450De Cos Guerra, Olga (2004): "Valoración del método de densidades focales (kernel) para la identificación de los patrones espaciales de crecimiento de la población de Espa-a", Geofocus, 4, pp. 136-165.Eicher, C. L., & Brewer, C. A. (2001). Dasymetric Mapping and Areal Interpolation: Implementation and Evaluation. Cartography and Geographic Information Science, 28(2), 125-138. doi:10.1559/152304001782173727Gallego, F. J., Batista, F., Rocha, C., & Mubareka, S. (2011). Disaggregating population density of the European Union with CORINE land cover. International Journal of Geographical Information Science, 25(12), 2051-2069. doi:10.1080/13658816.2011.583653García González, J. A. y Cebrián Abellán, F. (2006): "La interpolación como método de representación cartográfica para la distribución de la población: Aplicación a la provincia de Albacete", ponencia presentada en el XII Congreso Nacional de Tecnologías de la Información Geográfica, Granada, 19-23 de septiembre de 2006.Goerlich, F. J. y Cantarino, I. (2011): "Population Grid for Spain – SIOSE", presentado en el European Forum for Geography and Statistics Conference (EFGS), Lisboa (Portugal), 12-14 de octubre de 2011.Goerlich, F. J. y Cantarino, I. (2012): Una grid de densidad poblacional para Espa-a . Informe Economía y Sociedad, Bilbao, Fundación BBVA, 182 pp.Goerlich, F. J., & Cantarino, I. (2013). A population density grid for Spain. International Journal of Geographical Information Science, 27(12), 2247-2263. doi:10.1080/13658816.2013.799283Goerlich, F. J. y Cantarino, I. (2014): "Comparing bottom-up and top-down population density grids: The Spanish Census 2011", presentado en el European Forum for Geography and Statistics Conference (EFGS), Cracovia (Polonia), 22-24 de octubre de 2014.Goerlich, F. J., Ruiz, F., Chorén, P. y Albert, C. (2015): Cambios en la estructura y localización de la población: una visión de largo plazo (1842-2011), Bilbao, Fundación BBVA, 354 pp.Kumar, N. (2012): "Spatial sampling design for a demographic and health survey", Population Research Policy Review, 26/5, pp. 581-599.Martin, D., Tate, N. J., & Langford, M. (2000). Refining Population Surface Models: Experiments with Northern Ireland Census Data. Transactions in GIS, 4(4), 343-360. doi:10.1111/1467-9671.00060Mennis, J., & Hultgren, T. (2006). Intelligent Dasymetric Mapping and Its Application to Areal Interpolation. Cartography and Geographic Information Science, 33(3), 179-194. doi:10.1559/152304006779077309Ojeda, J., Márquez, J. y Álvarez, J. I. (2012): "Análisis de redes y sensibilidad a la unidad mínima de información poblacional: Sanlúcar de Barrameda (Cádiz)", en XV Congreso Nacional de Tecnologías de la Información Geográfica, AGE-CSIC, Madrid.Santos Preciado, J. M. (2015). La cartografía catastral y su utilización en la desagregación de la población. Aplicación al análisis de la distribución espacial de la población en el municipio de Leganés (Madrid). Estudios Geográficos, 76(278), 309-333. doi:10.3989/estgeogr.201511Steinocher, K. (2011a): "The European Dataset: The disaggregation issue", presentado en el European Forum for Geography and Statistics Conference (EFGS), Lisboa (Portugal). 12-14 de octubre de 2011.Steinocher, K. (2011b): "A new population grid for Europe – chances and challenges", presentado en el European Forum for Geography and Statistics Conference (EFGS), Lisboa (Portugal), 12-14 de octubre de 2011.Vinuesa Angulo, J. (1976): El Desarrollo Metropolitano de Madrid: Sus Repercusiones Geodemográficas, Madrid, Instituto de Estudios Madrile-os, 364 pp.Wang, J.-F., Stein, A., Gao, B.-B., & Ge, Y. (2012). A review of spatial sampling. Spatial Statistics, 2, 1-14. doi:10.1016/j.spasta.2012.08.00

Masses, radii, and orbits of small Kepler planets : The transition from gaseous to rocky planets

We report on the masses, sizes, and orbits of the planets orbiting 22 Kepler stars. There are 49 planet candidates around these stars, including 42 detected through transits and 7 revealed by precise Doppler measurements of the host stars. Based on an analysis of the Kepler brightness measurements, along with high-resolution imaging and spectroscopy, Doppler spectroscopy, and (for 11 stars) asteroseismology, we establish low false-positive probabilities (FPPs) for all of the transiting planets (41 of 42 have an FPP under 1%), and we constrain their sizes and masses. Most of the transiting planets are smaller than three times the size of Earth. For 16 planets, the Doppler signal was securely detected, providing a direct measurement of the planet's mass. For the other 26 planets we provide either marginal mass measurements or upper limits to their masses and densities; in many cases we can rule out a rocky composition. We identify six planets with densities above 5 g cm-3, suggesting a mostly rocky interior for them. Indeed, the only planets that are compatible with a purely rocky composition are smaller than 2 R ⊕. Larger planets evidently contain a larger fraction of low-density material (H, He, and H2O).Peer reviewedFinal Accepted Versio

Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

This paper presents measurements of the $W^+ \rightarrow \mu^+\nu$ and $W^- \rightarrow \mu^-\nu$ cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

Delivering 21st century Antarctic and Southern Ocean science

The Antarctic Roadmap Challenges (ARC) project identified critical requirements to deliver high priority Antarctic research in the 21st century. The ARC project addressed the challenges of enabling technologies, facilitating access, providing logistics and infrastructure, and capitalizing on international co-operation. Technological requirements include: i) innovative automated in situ observing systems, sensors and interoperable platforms (including power demands), ii) realistic and holistic numerical models, iii) enhanced remote sensing and sensors, iv) expanded sample collection and retrieval technologies, and v) greater cyber-infrastructure to process ‘big data’ collection, transmission and analyses while promoting data accessibility. These technologies must be widely available, performance and reliability must be improved and technologies used elsewhere must be applied to the Antarctic. Considerable Antarctic research is field-based, making access to vital geographical targets essential. Future research will require continent- and ocean-wide environmentally responsible access to coastal and interior Antarctica and the Southern Ocean. Year-round access is indispensable. The cost of future Antarctic science is great but there are opportunities for all to participate commensurate with national resources, expertise and interests. The scope of future Antarctic research will necessitate enhanced and inventive interdisciplinary and international collaborations. The full promise of Antarctic science will only be realized if nations act together