1,033 research outputs found

    Multiwavelength observations of a bright impact flash during the January 2019 total lunar eclipse

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    We discuss here a lunar impact flash recorded during the total lunar eclipse that occurred on 2019 January 21, at 4h 41m 38.09 +- 0.01 s UT. This is the first time ever that an impact flash is unambiguously recorded during a lunar eclipse and discussed in the scientific literature, and the first time that lunar impact flash observations in more than two wavelengths are reported. The impact event was observed by different instruments in the framework of the MIDAS survey. It was also spotted by casual observers that were taking images of the eclipse. The flash lasted 0.28 seconds and its peak luminosity in visible band was equivalent to the brightness of a mag. 4.2 star. The projectile hit the Moon at the coordinates 29.2 +- 0.3 ^{\circ}S, 67.5 +- 0.4 ^{\circ}W. In this work we have investigated the most likely source of the projectile, and the diameter of the new crater generated by the collision has been calculated. In addition, the temperature of the lunar impact flash is derived from the multiwavelength observations. These indicate that the blackbody temperature of this flash was of about 5700 K.Comment: Accepted for publication in MNRAS on 2019 March 2

    Colorful Imprints of Heavy States in the Electroweak Effective Theory

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    We analyze heavy states from generic ultraviolet completions of the Standard Model in a model-independent way and investigate their implications on the low-energy couplings of the electroweak effective theory. We build a general effective Lagrangian, implementing the electroweak symmetry breaking SU(2)LSU(2)RSU(2)L+RSU(2)_L\otimes SU(2)_R\to SU(2)_{L+R} with a non-linear Nambu-Goldstone realization, which couples the known particles to the heavy states. We generalize the formalism developed in previous works~[1,2] to include colored resonances, both of bosonic and fermionic type. We study bosonic heavy states with JP=0±J^P=0^\pm and JP=1±J^P=1^\pm, in singlet or triplet SU(2)L+RSU(2)_{L+R} representations and in singlet or octet representations of SU(3)CSU(3)_C, and fermionic resonances with J=12J=\frac{1}{2} that are electroweak doublets and QCD triplets or singlets. Integrating out the heavy scales, we determine the complete pattern of low-energy couplings at the lowest non-trivial order. Some specific types of (strongly- and weakly-coupled) ultraviolet completions are discussed to illustrate the generality of our approach and to make contact with current experimental searches.Comment: 51 pages, 2 figures, 12 tables; v2: matches Journal versio

    Short-term variability of comet C/2012 S1 (ISON) at 4.8 AU from the Sun

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    We observed comet C/2012 S1 (ISON) during six nights in February 2013 when it was at 4.8 AU from the sun. At this distance and time the comet was not very active and it was theoretically possible to detect photometric variations likely due to the rotation of the cometary nucleus. The goal of this work is to obtain differential photometry of the comet inner coma using different aperture radii in order to derive a possible rotational period. Large field of view images were obtained with a 4k x 4k CCD at the f/3 0.77m telescope of La Hita Observatory in Spain. Aperture photometry was performed in order to get relative magnitude variation versus time. Using calibrated star fields we also obtained ISON's R-magnitudes versus time. We applied a Lomb-Scargle periodogram analysis to get possible periodicities for the observed brightness variations, directly related with the rotation of the cometary nucleus. The comet light curve obtained is very shallow, with a peak-to-peak amplitude of 0.03 ±\pm 0.02 mag. A tentative synodic rotational period (single-peaked) of 14.4 ±\pm 1.2 hours for ISON's nucleus is obtained from our analysis, but there are other possibilities. We studied the possible effect of the seeing variations in the obtained periodicities during the same night, and from night to night. These seeing variations had no effect on the derived periodicity. We discuss and interpret all possible solutions for the rotational period of ISON's nucleus.Comment: 15 pages, 3 Figures, 2 Tables, accepted for publication in A&

    A study of the change in the instrumental variable of the monetary control outline in Spain

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    Incluye bibliografíaThis research is part of a wider project to construct an econometric model for the Spanish economy's monetary sector. It analyses the behaviour of the Bank of Spain from the standpoint of the obtaining of functional formas which summarise appropriately its monetary policy conduc

    Realidad aumentada, realidad virtual e interacción tangible para la educación

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    La línea de investigación y desarrollo presentada consiste en estudiar, desarrollar y evaluar aplicaciones de realidad virtual, realidad aumentada y juegos, en particular para apoyar los procesos de enseñanzaaprendizaje. Uno de los principales objetivos es la formación de recursos humanos y fortalecimiento de la investigación mediante el trabajo intergrupal entre diferentes instituciones annacionales y extranjeras.Eje: Tecnología Informática Aplicada en Educación

    Local models-based regression trees for very short-term wind speed prediction

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    This paper evaluates the performance of different types of Regression Trees (RTs) in a real problem of very short-term wind speed prediction from measuring data in wind farms. RT is a solidly established methodology that, contrary to other soft-computing approaches, has been under-explored in problems of wind speed prediction in wind farms. In this paper we comparatively evaluate eight different types of RTs algorithms, and we show that they are able obtain excellent results in real problems of very short-term wind speed prediction, improving existing classical and soft-computing approaches such as multi-linear regression approaches, different types of neural networks and support vector regression algorithms in this problem.We also show that RTs have a very small computation time, that allows the retraining of the algorithms whenever new wind speed data are collected from the measuring towers.Ministerio de Ciencia y Tecnología ECO2010-22065-C03-02Ministerio de Ciencia y Tecnología TIN2011-28956-C02Junta de Andalucía P12-TIC-1728Universidad Pablo de Olavide APPB81309

    Hacia una Minería Sostenible en el 95 entorno del Parque Natural del Alto Tajo. La escombrera experimental de la mina ‘El Machorro’(Poveda de la Sierra, Guadalajara)

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    Por su situación en el entorno de un espacio natural protegido, y sobre una ladera de pendiente y longitud elevadas, la restauración de la mina El Machorro constituye un importante reto científico y profesional. La empresa propietaria de esta mina, CAOBAR S.A., tiene entre sus objetivos demostrar la compatibilidad de la actividad minera con la conservación del medio ambiente. Por todo ello está acometiendo sucesivas revisiones de su Plan de Restauración del Espacio Natural (PREN), tratando de incorporar las mejores prácticas internacionales al respecto. Todo ello en colaboración con las universidades Complutense y de Alcalá (Madrid) y bajo la supervisión de la Dirección del Parque Natural del Alto Tajo. Una de las acciones más destacadas a ese respecto ha sido la construcción de una escombrera experimental, específicamente diseñada para mejorar la restauración de los terrenos afectados por la mina. En ella se estudia el comportamiento erosivo que tienen diferentes diseños de escombreras mediante la combinación de: (a) distintas topografías (cóncava y en terrazas); (b) distintos tipos de sustrato (estériles, coluviones y suelos originales); y (c) distintos tipos de revegetación (como hidrosiembras). En la comunicación se describen los detalles de la puesta en funcionamiento de esta escombrera experimental, así como los resultados obtenidos para el periodo 1 de noviembre de 2008 a 31 de marzo de 2009

    Results from the 2014 november 15th. multi-chord stellar occultation by the TNO (229762) 2007 UK126

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    Benedetti-Rossi, G. et. al.We present results derived from the first multi-chord stellar occultation by the trans-Neptunian object (229762) 2007 UK, observed on 2014 November 15. The event was observed by the Research and Education Collaborative Occultation Network project and International Occultation Timing Association collaborators throughout the United States. Use of two different data analysis methods obtain a satisfactory fit to seven chords, yielding an elliptical fit to the chords with an equatorial radius of R = 338 km and equivalent radius of R = 319 km. A circular fit also gives a radius of R = 324 km. Assuming that the object is a Maclaurin spheroid with indeterminate aspect angle, and using two published absolute magnitudes for the body, we derive possible ranges for geometric albedo between p = 0.159 and p = 0.189 , and for the body oblateness between ∈ = 0.105 and ∈ = 0.118 . For a nominal rotational period of 11.05 hr, an upper limit for density of ρ = 1740 kg m is estimated for the body.The RECON project would not be possible without all of the support from our community teams (teachers, students, and community members) and was funded by NSF grants AST-1212159, AST-1413287, and AST-1413072. Special thanks to Dean and Starizona for their support of RECON above and beyond the usual bounds of a commercial relationship. Part of the research leading to these results has received funding from the European Research Council under the European Community's H2020 (2014-2020/ERC Grant Agreement n 669416 >LUCKY STAR>). Funding from Spanish grant AYA-2014-56637-C2-1-P is acknowledged, as is the Proyecto de Excelencia de la Junta de Andaluca, J. A. 2012-FQM1776. R.D. acknowledges the support of MINECO for his Ramon y Cajal Contract. FEDER funds are also acknowledged. A.D.O. is thankful for the support of the CAPES (BEX 9110/12-7) FAPERJ/PAPDRJ (E-26/200.464/2015) grants. G.B.R. is thankful for the support of CAPES/Brazil and FAPERJ (Grant E-01/2015/209545). J.I.B.C. acknowledges CNPq for a PQ2 fellowship (process number 308489/2013-6). L.G. thanks the support from CONACYT through grant 167236. M.A. thanks the CNPq (Grants 473002/2013-2 and 308721/2011-0) and FAPERJ (Grant E-26/111.488/2013). P.S.-S. acknowledges that part of the research leading to these results has received funding from the European Unions Horizon 2020 Research and Innovation Programme, under Grant Agreement no 687378. R.V.M. acknowledges the following grants: CNPq-306885/2013, CAPES/Cofecub-2506/2015, FAPERJ/PAPDRJ-45/2013, FAPERJ/CNE/05-2015.Peer Reviewe
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