Suchergebnisse

La escuela pública responde a un conjunto de presiones desde política pública, globalización, contexto y tradición, que configuran y buscan orientar, controlar y explicar las versiones discursivas en los procesos generados en su interior. En ese marco, la presente tesis se propone indagar y reflexionar el saber disciplinar escolar. ¿Cómo pasa una disciplina académica o científica a ser objeto de enseñanza y medio de formación? ¿Qué queda de la disciplina en ese proceso? Desde un análisis arqueológico, se abordan los discursos de la legislación en dos coyunturas: la emergencia de las leyes 115/94 y 715/01, identificando cinco objetos de discurso que se configuran como dispositivos de control de los procesos escolares: la financiación, la gestión escolar, el horizonte de formación, el currículo y la evaluación. Prácticas discursivas que se han implantado en la escuela y que involucran también el ejercicio del poder como flujo tensional de las relaciones humanas influenciando la posición particular de sujeto - maestro respecto a su saber disciplinar. El análisis arqueológico se complementa con un estudio autobiográfico pedagógico por los autores, (formados en una disciplina: Filosofía, Educación Física y Ciencias Sociales) que permite enlazar los objetos de discurso con las contingencias emergentes en la cotidianidad escolar. ; Public schools answer to a set of pressures from the public policies, globalization, context and tradition, which configure and seek to guide, control, and explain the discursive versions in the internal generated processes. In this area, this thesis proposes to inquire and reflect the disciplinary knowledge of the school. How does an academic or scientific discipline become a teaching object and an education mean? What is left from the discipline in this process? From an archeological analysis, legislation discourses are dealt from two junctures: The emergence of the laws 115/94 and 715/01, identifying five discourse objects which are configured as control devices of school processes: Funding, scholar management, formation s horizon, curriculum and evaluation. Discursive practices which have been implemented in school and that involve also the exercise of power as a tensional flux of the human relations , influencing the particular position of the subject the master with respect to his disciplinary knowledge. The archeological analysis is complemented by an autobiographic-pedagogic study (formed in a discipline: Philosophy, physical education and social sciences) which allows to link the discourse objects with the emergent contingences of the school everydayness .

Surveys have shown that super-Earth and Neptune-mass exoplanets are more frequent than gas giants around low-mass stars, as predicted by the core accretion theory of planet formation. We report the discovery of a giant planet around the very-low-mass star GJ 3512, as determined by optical and near-infrared radial-velocity observations. The planet has a minimum mass of 0.46 Jupiter masses, very high for such a small host star, and an eccentric 204-day orbit. Dynamical models show that the high eccentricity is most likely due to planet-planet interactions. We use simulations to demonstrate that the GJ 3512 planetary system challenges generally accepted formation theories, and that it puts constraints on the planet accretion and migration rates. Disk instabilities may be more efficient in forming planets than previously thought.Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science ; This research was supported by the following programs, grants, and fellowships: Spanish Ministry for Science, Innovation and Universities (MCIU) ESP2014-54062-R, ESP2014-54362P, AYA2015-69350-C3-2-P, BES-2015-074542, AYA2016-79425-C3-1/2/3-P, ESP2016-76076-R, ESP2016-80435-C2-1-R, ESP2016-80435-C2-2-R, ESP2017-87143-R, ESP2017-87676-C05-02-R, ESP-2017-87676-2-2, RYC-2012-09913 (>Ramon y Cajal> program), and FPU15/01476; Israel Science Foundation grant 848/16, CONICYT-FONDECYT/Chile Postdoctorado 3180405; Deutsches Zentrum fur Luft-un Raumfahrt (DLR) 50OW0204 and 50OO1501; Italian Minister of Instruction, University and Research (MIUR), FFABR 2017; University of Rome Tor Vergata, >Mission: Sustainability 2016> fund; European Research Council under the European Union Horizon 2020 research and innovation program 694513; Mexican national council for science and technology CONACYT, CVU 448248; the >Center of Excellence Severo Ochoa> award for the Instituto de Astrofisica de Andalucia (SEV-2017-0709); Generalitat de Catalunya/CERCA program; Fondo Europeo de Desarollo Regional (FEDER); German Science Foundation (DFG) Research Unit FOR2544 >Blue Planets around Red Stars> and Priority Programs SPP 1833, >Building a Habitable Earth> and SPP 1992, >Exploring the Diversity of Extrasolar Planets> NSF grants PHY17-48958 and PHY-1607761; Swiss National Science Foundation under grant BSGIO_155816 >PlaneltsInTime' and within the framework of the NCCR PlanetS; Queen Mary University of London Scholarship and STFC Consolidated Grant ST/P000592/1; Spanish MCIU FPI-SO predoctoral contract BES-2017-082610 and the Knut and Alice Wallenberg Foundation.

The appendix tables are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/609/A117 ; Context. The main goal of the CARMENES survey is to find Earth-mass planets around nearby M-dwarf stars. Seven M dwarfs included in the CARMENES sample had been observed before with HIRES and HARPS and either were reported to have one short period planetary companion (GJ 15 A, GJ 176, GJ 436, GJ 536 and GJ 1148) or are multiple planetary systems (GJ 581 and GJ 876). Aims. We aim to report new precise optical radial velocity measurements for these planet hosts and test the overall capabilities of CARMENES. Methods. We combined our CARMENES precise Doppler measurements with those available from HIRES and HARPS and derived new orbital parameters for the systems. Bona-fide single planet systems were fitted with a Keplerian model. The multiple planet systems were analyzed using a self-consistent dynamical model and their best fit orbits were tested for long-term stability. Results. We confirm or provide supportive arguments for planets around all the investigated stars except for GJ 15 A, for which we find that the post-discovery HIRES data and our CARMENES data do not show a signal at 11.4 days. Although we cannot confirm the super-Earth planet GJ 15 Ab, we show evidence for a possible long-period (P = 7030 d) Saturn-mass (msini = 51.8M) planet around GJ 15 A. In addition, based on our CARMENES and HIRES data we discover a second planet around GJ 1148, for which we estimate a period P = 532.6 days, eccentricity e = 0.342 and minimum mass msini = 68.1M. Conclusions. The CARMENES optical radial velocities have similar precision and overall scatter when compared to the Doppler measurements conducted with HARPS and HIRES. We conclude that CARMENES is an instrument that is up to the challenge of discovering rocky planets around low-mass stars.© ESO, 2018. ; CARMENES is an instrument for the Centro Astronomico Hispano-Aleman de Calar Alto (CAHA, Almeria, Spain). CARMENES is funded by the German Max-Planck-Gesellschaft (MPG), the Spanish Consejo Superior de Investigaciones Cientificas (CSIC), the European Union through FEDER/ERF FICTS-2011-02 funds, and the members of the CARMENES Consortium (Max-Planck-Institut fur Astronomie, Instituto de Astrofisica de Andalucia, Landessternwarte Konigstuhl, Institut de Ciencies de l'Espai, Insitut fur Astrophysik Gottingen, Universidad Complutense de Madrid, Thuringer Landessternwarte Tautenburg, Instituto de Astrofisica de Canarias, Hamburger Sternwarte, Centro de Astrobiologia and Centro Astronomico Hispano-Aleman), with additional contributions by the Spanish Ministry of Economy, the German Science Foundation (DFG), the Klaus Tschira Stiftung, the states of Baden-Wurttemberg and Niedersachsen, the DFG Research Unit FOR2544 >Blue Planets around Red Stars>, and by the Junta de Andalucia. This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. This work used the Systemic Console package (Meschiari et al. 2009) for cross-checking our Keplerian and Dynamical fits and the python package astroML (VanderPlas et al. 2012) for the calculation of the GLS periodogram. The IEEC-CSIC team acknowledges support by the Spanish Ministry of Economy and Competitiveness (MINECO) and the Fondo Europeo de Desarrollo Regional (FEDER) through grant ESP2016-80435-C2-1-R, as well as the support of the Generalitat de Catalunya/CERCA programme. The IAA-CSIC team acknowledges support by the Spanish Ministry of Economy and Competitiveness (MINECO) through grants AYA2014-54348-C03-01 and AYA2016-79425-C3-3-P as well as FEDER funds. The UCM team acknowledges support by the Spanish Ministry of Economy and Competitiveness (MINECO) from projects AYA2015-68012-C2-2-P and AYA2016-79425- C3-1,2,3-P and the Spanish Ministerio de Educacion, Cultura y Deporte, programa de Formacion de Profesorado Universitario, under grant FPU15/01476. T. T. and M.K. thank to Jan Rybizki for the very helpful discussion in the early phases of this work. V.J.S.B. is supported by grant AYA2015-69350-C3-2-P from the Spanish Ministry of Economy and Competiveness (MINECO). J.C.S. acknowledges funding support from Spanish public funds for research under project ESP2015-65712-C5-5-R (MINECO/FEDER), and under Research Fellowship program >Ramon y Cajal> with reference RYC2012-09913 (MINECO/FEDER). The contributions of M.A. were supported by DLR (Deutsches Zentrum fur Luft- und Raumfahrt) through the grants 50OW0204 and 50OO1501. J.L.-S. acknowledges the Office of Naval Research Global (award No. N62909-15- 1-2011) for support. C.d.B. acknowledges that this work has been supported by Mexican CONACyT research grant CB-2012-183007 and the Spanish Ministry of Economy and Competitivity through projects AYA2014-54348-C3-2-R. J.I.G.H., and R.R. acknowledge financial support from the Spanish Ministry project MINECO AYA2014-56359-P. J.I.G.H. also acknowledges financial support from the Spanish MINECO under the 2013 Ramon y Cajal program MINECO RYC-2013-14875. V. Wolthoff acknowledges funding from the DFG Research Unit FOR2544 >Blue Planets around Red Stars>, project No. RE 2694/4-1.We thank the anonymous referee for the excellent comments that helped to improve the quality of this paper.

Context. Teegarden's Star is the brightest and one of the nearest ultra-cool dwarfs in the solar neighbourhood. For its late spectral type (M7.0 V), the star shows relatively little activity and is a prime target for near-infrared radial velocity surveys such as CARMENES. Aims. As part of the CARMENES search for exoplanets around M dwarfs, we obtained more than 200 radial-velocity measurements of Teegarden's Star and analysed them for planetary signals. Methods. We find periodic variability in the radial velocities of Teegarden's Star. We also studied photometric measurements to rule out stellar brightness variations mimicking planetary signals. Results. We find evidence for two planet candidates, each with 1.1 M minimum mass, orbiting at periods of 4.91 and 11.4 d, respectively. No evidence for planetary transits could be found in archival and follow-up photometry. Small photometric variability is suggestive of slow rotation and old age. Conclusions. The two planets are among the lowest-mass planets discovered so far, and they are the first Earth-mass planets around an ultra-cool dwarf for which the masses have been determined using radial velocities.© ESO 2019. ; M.Z. acknowledges support from the Deutsche Forschungsgemeinschaft under DFG RE 1664/12-1 and Research Unit FOR2544 >Blue Planets around Red Stars>, project no. RE 1664/14-1. CARMENES is an instrument for the Centro Astronomico Hispano-Aleman de Calar Alto (CAHA, Almeria, Spain). CARMENES is funded by the German Max-Planck-Gesellschaft (MPG), the Spanish Consejo Superior de Investigaciones Cientificas (CSIC), the European Union through FEDER/ERF FICTS-2011-02 funds, and the members of the CARMENES Consortium (Max-Planck-Institut fur Astronomie, Instituto de Astrofisica de Andalucia, Landessternwarte Konigstuhl, Institut de Ciencies de l'Espai, Institut fur Astrophysik Gottingen, Universidad Complutense de Madrid, Thuringer Landessternwarte Tautenburg, Instituto de Astrofisica de Canarias, Hamburger Sternwarte, Centro de Astrobiologia and Centro Astronomico Hispano-Aleman), with additional contributions by the Spanish Ministry of Economy, the German Science Foundation through the Major Research Instrumentation Programme and DFG Research Unit FOR2544 >Blue Planets around Red Stars>, the Klaus Tschira Stiftung, the states of Baden-Wurttemberg and Niedersachsen, and by the Junta de Andalucia. Based on data from the CARMENES data archive at CAB (INTA-CSIC). This article is based on observations made with the MuSCAT2 instrument, developed by ABC, at Telescopio Carlos Sanchez operated on the island of Tenerife by the IAC in the Spanish Observatorio del Teide. Data were partly collected with the 150-cm and 90-cm telescopes at the Sierra Nevada Observatory (SNO) operated by the Instituto de Astrofisica de Andalucia (IAA-CSIC). Data were partly obtained with the MONET/South telescope of the MOnitoring NEtwork of Telescopes, funded by the Alfried Krupp von Bohlen und Halbach Foundation, Essen, and operated by the Georg-August-Universitat Gottingen, the McDonald Observatory of the University of Texas at Austin, and the South African Astronomical Observatory. We acknowledge financial support from the Spanish Agencia Estatal de Investigacion of the Ministerio de Ciencia, Innovacion y Universidades and the European FEDER/ERF funds through projects AYA2015-69350-C3-2-P, AYA2016-79425-C3-1/2/3-P, AYA2018-84089, BES-2017-080769, BES-2017-082610, ESP2015-65712-C5-5-R, ESP2016-80435-C2-1/2-R, ESP2017-87143-R, ESP2017-87676-2-2, ESP2017-87676-C5-1/2/5-R, FPU15/01476, RYC-2012-09913, the Centre of Excellence >Severo Ochoa> and >Maria de Maeztu> awards to the Instituto de Astrofisica de Canarias (SEV-2015-0548), Instituto de Astrofisica de Andalucia (SEV-2017-0709), and Centro de Astrobiologia (MDM-2017-0737), the Generalitat de Catalunya through CERCA programme>, the Deutsches Zentrum fur Luft-und Raumfahrt through grants 50OW0204 and 50OO1501, the European Research Council through grant 6 94 513, the Italian Ministero dell'instruzione, dell'universita de della ricerca and Universita degli Studi di Roma Tor Vergata through FFABR 2017 and >Mission: Sustainability 2016>, the UK Science and Technology Facilities Council through grant ST/P000592/1, the Israel Science Foundation through grant 848/16, the Chilean CONICYT-FONDECYT through grant 31 80 405, the Mexican CONACYT through grant CVU 4 48 248, the JSPS KAKENHI through grants JP18H01265 and 18H05439, and the JST PRESTO through grant JPMJPR1775. ; Peer Reviewed

The CARMENES radial velocity (RV) survey is observing 324 M dwarfs to search for any orbiting planets. In this paper, we present the survey sample by publishing one CARMENES spectrum for each M dwarf. These spectra cover the wavelength range 520¿1710 nm at a resolution of at least R >80 000, and we measure its RV, H¿ emission, and projected rotation velocity. We present an atlas of high-resolution M-dwarf spectra and compare the spectra to atmospheric models. To quantify the RV precision that can be achieved in low-mass stars over the CARMENES wavelength range, we analyze our empirical information on the RV precision from more than 6500 observations. We compare our high-resolution M-dwarf spectra to atmospheric models where we determine the spectroscopic RV information content, Q, and signal-to-noise ratio. We find that for all M-type dwarfs, the highest RV precision can be reached in the wavelength range 700¿900 nm. Observations at longer wavelengths are equally precise only at the very latest spectral types (M8 and M9). We demonstrate that in this spectroscopic range, the large amount of absorption features compensates for the intrinsic faintness of an M7 star. To reach an RV precision of 1 m s¿1 in very low mass M dwarfs at longer wavelengths likely requires the use of a 10 m class telescope. For spectral types M6 and earlier, the combination of a red visual and a near-infrared spectrograph is ideal to search for low-mass planets and to distinguish between planets and stellar variability. At a 4 m class telescope, an instrument like CARMENES has the potential to push the RV precision well below the typical jitter level of 3-4 m s-1. © ESO 2018. ; We thank an anonymous referee for prompt attention and helpful comments that helped to improve the quality of this paper. CARMENES is an instrument for the Centro Astronomico Hispano-Aleman de Calar Alto (CAHA, Almeria, Spain). CARMENES is funded by the German Max-Planck-Gesellschaft (MPG), the Spanish Consejo Superior de Investigaciones Cientificas (CSIC), the European Union through FEDER/ERF FICTS-2011-02 funds, and the members of the CARMENES Consortium (Max-Planck-Institut fur Astronomie, Instituto de Astrofisica de Andalucia, Landessternwarte Konigstuhl, Institut de Ciencies de l'Espai, Insitut fur Astrophysik Gottingen, Universidad Complutense de Madrid, Thuringer Landessternwarte Tautenburg, Instituto de Astrofisica de Canarias, Hamburger Sternwarte, Centro de Astrobiologia and Centro Astronomico Hispano-Aleman), with additional contributions by the Spanish Ministry of Economy, the German Science Foundation through the Major Research Instrumentation Programme and DFG Research Unit FOR2544 >Blue Planets around Red Stars>, the Klaus Tschira Stiftung, the states of Baden-Wurttemberg and Niedersachsen, and by the Junta de Andalucia. This work has made use of the VALD database, operated at Uppsala University, the Institute of Astronomy RAS in Moscow, and the University of Vienna. We acknowledge the following funding programs: European Research Council (ERC-279347), Deutsche Forschungsgemeinschaft (RE 1664/12-1, RE 2694/4-1), Bundesministerium fur Bildung und Forschung (BMBF-05A14MG3, BMBF-05A17MG3), Spanish Ministry of Economy and Competitiveness (MINECO, grants AYA2015-68012-C2-2-P, AYA2016-79425-C3-1,2,3-P, AYA2015-69350-C3-2-P, AYA2014-54348-C03-01, AYA2014-56359-P, AYA2014-54348-C3-2R, AYA2016-79425-C3-3-P and 2013 Ramon y Cajal program RYC-2013-14875), Fondo Europeo de Desarrollo Regional (FEDER, grant ESP2016-80435-C2-1-R, ESP2015-65712-C5-5-R), Generalitat de Catalunya/CERCA programme, Spanish Ministerio de Educacion, Cultura y Deporte, programa de Formacion de Profesorado Universitario (grant FPU15/01476), Deutsches Zentrum fur Luft- und Raumfahrt (grants 50OW0204 and 50OO1501), Office of Naval Research Global (award no. N62909-15-1-2011), Mexican CONACyT grant CB-2012-183007.

The design and construction of CARMENES has been presented at previous SPIE conferences. It is a next-generation radial-velocity instrument at the 3.5m telescope of the Calar Alto Observatory, which was built by a consortium of eleven Spanish and German institutions. CARMENES consists of two separate échelle spectrographs covering the wavelength range from 0.52 to 1.71¿m at a spec-tral resolution of R < 80,000, fed by fibers from the Cassegrain focus of the telescope. CARMENES saw ¿First Light¿ on Nov 9, 2015. During the commissioning and initial operation phases, we established basic performance data such as throughput and spectral resolution. We found that our hollow-cathode lamps are suitable for precise wavelength calibration, but their spectra contain a number of lines of neon or argon that are so bright that the lamps cannot be used in simultaneous exposures with stars. We have therefore adopted a calibration procedure that uses simultaneous star / Fabry Pérot etalon exposures in combination with a cross-calibration between the etalons and hollow-cathode lamps during daytime. With this strategy it has been possible to achieve 1-2 m/s precision in the visible and 5-10 m/s precision in the near-IR; further improvements are expected from ongoing work on temperature control, calibration procedures and data reduction. Comparing the RV precision achieved in different wavelength bands, we find a ¿sweet spot¿ between 0.7 and 0.8¿m, where deep TiO bands provide rich RV information in mid-M dwarfs. This is in contrast to our pre-survey models, which predicted comparatively better performance in the near-IR around 1¿m, and explains in part why our near-IR RVs do not reach the same precision level as those taken with the visible spectrograph. We are now conducting a large survey of 340 nearby M dwarfs (with an average distance of only 12pc), with the goal of finding terrestrial planets in their habitable zones. We have detected the signatures of several previously known or suspected planets and also discovered several new planets. We find that the radial velocity periodograms of many M dwarfs show several significant peaks. The development of robust methods to distinguish planet signatures from activity-induced radial velocity jitter is therefore among our priorities. Due to its large wavelength coverage, the CARMENES survey is generating a unique data set for studies of M star atmospheres, rotation, and activity. The spectra cover important diagnostic lines for activity (H alpha, Na I D1 and D2, and the Ca II infrared triplet), as well as FeH lines, from which the magnetic field can be inferred. Correlating the time series of these features with each other, and with wavelength-dependent radial velocities, provides excellent handles for the discrimination between planetary companions and stellar radial velocity jitter. These data are also generating new insight into the physical properties of M dwarf atmospheres, and the impact of activity and flares on the habitability of M star planets. © 2018 SPIE. ; CARMENES is an instrument for the Centro Astronomico Hispano-Aleman de Calar Alto (CAHA, Almeria, Spain). CARMENES is funded by the German Max-Planck-Gesellschaft (MPG), the Spanish Consejo Superior de Investigaciones Cientificas (CSIC), the European Union through FEDER/ERF FICTS-2011-02 funds, and the members of the CARMENES Consortium (Max-Planck-Institut fur Astronomie, Instituto de Astrofisica de Andalucia, Landessternwarte Konigstuhl, Institut de Ciencies de l'Espai, Insitut fur Astrophysik Gottingen, Universidad Complutense de Madrid, Thuringer Landessternwarte Tautenburg, Instituto de Astrofisica de Canarias, Hamburger Sternwarte, Centro de Astrobiologia and Centro Astronomico Hispano-Aleman), with additional contributions by the Spanish Ministry of Science, the German Science Foundation through the Major Research Instrumentation Program and DFG Research Unit FOR2544 "Blue Planets around Red Stars", the Klaus Tschira Stiftung, the states of Baden-Wurttemberg and Niedersachsen, and by the Junta de Andalucia.