Examinando por Autor "Launhardt, R."

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Acceso Abierto
A giant exoplanet orbiting a very-low-mass star challenges planet formation models
(American Association for the Advancement of Science, 2019-09-27) Morales, J. C.; Mustill, A. J.; Ribas, I.; Davies, M. B.; Reiners, A.; Bauer, F. F.; Kossakowski, D.; Herrero, Enrique; Rodríguez, E.; López González, M. J.; Rodríguez López, C.; Stock, S.; Zechmeister, M.; Luque, R.; Gesa, L.; Pedraz, S.; Baroch, D.; Sarkis, P.; Lafarga, M.; Johnson, E. N.; Anglada Escudé, G.; González Álvarez, E.; Perryman, M. A. C.; Dreizler, S.; Sarmiento, L. F.; Tal Or, L.; Labarga, F.; Reffert, S.; Rebolo, R.; Schweitzer, A.; Schäfer, S.; Hagen, H. J.; Lázaro, F. J.; Quirrenbach, A.; Perger, M.; Guenther, E. W.; Schlecker, M.; Montes, D.; Jeffers, S. V.; Cortés Contreras, M.; Kürster, M.; Schmitt, J. H. M. M.; Aceituno, Francisco José; Abellán, F. J.; Rosich, A.; Aceituno, J.; Schöfer, P.; Arroyo Torres, B.; Amado, P. J.; Antona, R.; Solano, Enrique; Benítez, D.; Kaminski, A.; Becerril Jarque, S.; Sota, A.; Kehr, M.; Abril, M.; Brinkmöller, M.; Béjar, V. J. S.; Ammler von Eiff, M.; Calvo Ortega, R.; Zapatero Osorio, M. R.; Barrado, D.; Cardona Guillén, C.; Yan, F.; Bergond, G.; Casanova, V.; Klahr, H.; Chaturvedi, P.; Nagel, E.; Claret, A.; Trifonov, T.; Czesla, S.; Henning, T.; Dorda, R.; Seifert, W.; Fernández Hernández, Maite; Alonso Floriano, F. J.; Azzaro, M.; Berdiñas, Z. M.; Del Burgo, C.; Cano, J.; Carro, J.; Casasayas Barris, N.; Cifuentes, C.; Colomé, J.; Díez Alonso, E.; Emsenhuber, A.; Guàrdia, J.; Guijarro, A.; De Guindos, E.; Hatzes, Artie; Hauschildt, P. H.; Hedrosa, R. P.; Hermelo, I.; Hernández Arabi, R.; Hernández Otero, F.; Hintz, D.; Klüter, J.; González Peinado, R.; González Hernández, J. I.; González Cuesta, L.; De Juan, E.; Stahl, O.; Burn, R.; Kim, M.; Fernández Martín, A.; Lara, L. M.; Mordasini, C.; Labiche, N.; Cárdenas, M. C.; Lampón, M.; Ferro, I. M.; López del Fresno, M.; Passegger, V. M.; Lizon, Jean Louis; Casal, E.; Lodieu, N.; Fuhrmeister, B.; Mancini, L.; López Santiago, J.; Kemmer, J.; Mall, U.; Galadí Enríquez, D.; Martín Fernández, P.; Marfil, E.; Lalitha, S.; Martín, Eduardo L.; Gallardo Cava, I.; Mirabet, E.; Llamas, M.; Marvin, E. L.; García Vargas, M. L.; Nortmann, L.; Magán Madinabeitia, H.; Nelson, Richard; García Piquer, A.; Pallé, E.; Marín Molina, J. A.; Pascual Granado, J.; Caballero, J. A.; Martínez Rodríguez, H.; Pérez Medialdea, D.; Huke, P.; Naranjo, V.; Rabaza, O.; Huber, A.; Ofir, A.; Redondo, P.; Holgado, G.; Rodler, F.; Klutsch, A.; Sabotta, S.; Launhardt, R.; Salz, M.; López Salas, F. J.; Sánchez Carrasco, M. A.; Mandel, H.; Sanz Forcada, J.; Martín Ruiz, S.; Moya, A.; Nowak, G.; Pavlov, Alexander; Pérez Calpena, A.; Ramón Ballesta, A.; Rix, H. W.; Rodríguez Trinidad, A.; Sadegi, S.; Sánchez Blanco, E.; Sánchez López, A.; Stürmer, J.; Suárez, J. C.; Tabernero, H. M.; Tulloch, S. M.; Veredas, G.; Vico Linares, J. I.; Vilardell, F.; Wagner, K.; Winkler, J.; Wolthoff, V.; Johansen, A.; Stuber, T.; Israel Science Foundation (ISF); Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT); Swiss National Science Foundation (SNSF); Deutsches Zentrum für Luft- und Raumfahrt (DLR); Ministero dell'Istruzione, dell'Università e della Ricerca (MIUR); European Research Council (ERC); Generalitat de Catalunya; Deutsche Forschungsgemeinschaft (DFG); Queen Mary University of London; Consejo Nacional de Ciencia y Tecnología (CONACYT); Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737; Morales, J. C. [0000-0003-0061-518X]; Mustill, A. J. [0000-0002-2086-3642]; Ribas, I. [0000-0002-6689-0312]; Davies, M. B. [0000-0001-6080-1190]; Bauer, F. F. [0000-0003-1212-5225]; Herrrero, E. [0000-0001-8602-6639]; Rodríguez, E. [0000-0001-6827-9077]; López González, M. J. [0000-0001-8104-5128]; Rodríguez López, C. [0000-0001-5559-7850]; López González, M. J. [0000-0001-8104-5128]; Rodríguez López, C. [0000-0001-5559-7850]; Sarkis, P. [0000-0001-8128-3126]; López Santiago, J. [0000-0003-2402-8166]; Vilardell, F. [0000-0003-0441-1504]; Winkler, J. [0000-0003-0568-8820]; Nowak, G. [0000-0002-7031-7754]; Béjar, V. J. S. [0000-0002-5086-4232]; Luque, R. [0000-0002-4671-2957]; Pérez Calpena, A. [0000-0001-7361-9240]; Sota, A. [https://orcid.org/0000-0002-9404-6952]; Klahr, H. [0000-0002-8227-5467]; Mordasini, C. [0000-0002-1013-2811]; Rodler, F. [0000-0003-0650-5723]; Tabernero, H. [0000-0002-8087-4298]; Cortés Contreras, M. [0000-0003-3734-9866]; Lafarga, M. [0000-0002-8815-9416]; Sánchez López, A. [0000-0002-0516-7956]; Yan, F. [0000-0001-9585-9034]; Reffert, S. [0000-0002-0460-8289]; Rosich, A. [0000-0002-9141-3067]; Sarmiento, L. F. [0000-0002-8475-9705]; Perger, M. [0000-0001-7098-0372]; Sabotta, S. [0000-0001-9078-5574]; Guenther, E. W. [0000-0002-9130-6747]; Kaminski, A. [0000-0003-0203-8208]; Schmitt, J. H. M. M. [0000-0003-2554-9916]; Aceituno, J. [0000-0003-0487-1105]; Alonso Floriano, F. J. [0000-0003-1202-5734]; Stock, S. [0000-0002-1166-9338]; Nagel, E. [0000-0002-4019-3631]; Barrado, D. [0000-0002-5971-9242]; Tulloch, S. [0000-0003-0840-8521]; Trifonov, T. [0000-0002-0236-775X]; Bergond, G. [0000-0003-3132-9215]; Burn, R. [0000-0002-9020-7309]; Zapatero Osorio, M. R. [0000-0001-5664-2852]; Montes, D. [0000-0002-7779-238X]; Cano, J. [0000-0003-1984-5401]; Cardona Guillén, C. [0000-0002-2198-4200]; Baroch, D. [0000-0001-7568-5161]; Ammler-von Eiff, M. [0000-0001-9565-1698]; Chaturvedi, P. [0000-0002-1887-1192]; Cifuentes, C. [0000-0003-1715-5087]; Anglada Escudé, G. [0000-0002-3645-5977]; Becerril Jarque, S. [0000-0001-9009-1150]; González Cuesta, L. [0000-0002-1241-5508]; Díez Alonso, E. [0000-0002-5826-9892]; Emsenhuber, A. [0000-0002-8811-1914]; Passegger, V. M. [0000-0002-8569-7243]; García Vargas, M. L. [0000-0002-2058-3528]; González Álvarez, E. [0000-0002-4820-2053]; Amado, P. J. [0000-0002-8388-6040]; Carro, J. [0000-0002-0838-3603]; Guàrdia, J. [0000-0002-7191-9001]; Abellán, F. J. [0000-0002-5724-1636]; Colomé, J. [0000-0002-1678-2241]; Hermelo, I. [0000-0001-9178-694X]; Hintz, D. [0000-0002-5274-2589]; Arroyo Torres, B. [0000-0002-3392-4694]; Fuhrmeister, B. [0000-0001-8321-5514]; Johnson, E. [0000-0003-2260-5134]; De Juan Fernández, E. [0000-0002-9382-4505]; Berdiñas, Z. M. [0000-0002-6057-6461]; González Hernández, J. I. [0000-0002-0264-7356]; Klüter, J. [0000-0002-3469-5133]; Klutsch, A. [0000-0001-7869-3888]; Calvo Ortega, R. [0000-0003-3693-6030]; Guijarro, A. [0000-0001-5518-1759]; Aceituno, F. J. [0000-0001-8074-4760]; Lara, L. M. [0000-0002-7184-920X]; Launhardt, R. [0000-0002-8298-2663]; Casasayas Barris, N. [0000-0002-2891-8222]; López del Fresno, M. [0000-0002-9479-7780]; Magan Madinabeitia, H. [0000-0003-1243-4597]; Czesla, S. [0000-0002-4203-4773]; Kehr, M. [0000-0002-7420-7368]; Marín Molina, J. A. [0000-0002-3525-0806]; Galadí Enríquez, D. [0000-0003-4946-5653]; Labarga, F. [0000-0002-7143-0206]; Martínez Rodríguez, H. [0000-0002-1919-228X]; Marvin, C. J. [0000-0002-2249-2611]; González Peinado, R. [0000-0002-6658-8930]; Lizon, J. L. [0000-0001-8928-2566]; Naranjo, V. [0000-0003-0097-1061]; Nelson, R. [0000-0002-9687-8779]; De Guindos, E. [0000-0002-8124-9101]; Manici, L. [0000-0002-9428-8732]; Ofir, A. [0000-0002-9152-5042]; Pascual Granado, J. [0000-0003-0139-6951]; Huke, P. [0000-0001-5913-2743]; Martín, E. [0000-0002-1208-4833]; García Piquer, A. [0000-0002-6872-4262]; Rabaza, O. [0000-0003-2766-2103]; Ramón Ballesta, A. [0000-0002-4323-0610]; Kim, M. [0000-0001-6218-2004]; Rodríguez Trinidad, A. [0000-0002-3356-8634]; Sadegi, S. [0000-0001-9897-6121]; Lampón, M. [0000-0002-0183-7158]; Nortmann, L. [0000-0001-8419-8760]; Sanz Forcada, J. [0000-0002-1600-7835]; Lodieu, N. [0000-0002-3612-8968]; Pedraz, S. [0000-0003-1346-208X]; Schäfer, S. [0000-0001-8597-8048]; Schlecker, M. [0000-0001-8355-2107]; Marfil, E. [0000-0001-8907-4775]; Redondo, P. G. [0000-0001-5992-5778]; Schöfer, P. [0000-0002-5969-3708]; Solano, E. [0000-0003-1885-5130]; Martín Ruiz, S. [0000-0002-9006-7182]; Sánchez Carrasco, M. A. [0000-0001-5533-3660]; Stuber, T. [0000-0003-2185-0525]; Suárez, J. C. [0000-0003-3649-8384]; Moya, A. [0000-0003-1665-5389]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737; Centros de Excelencia Severo Ochoa, INSTITUTO DE ASTROFISICA DE ANDALUCIA (IAA), SEV-2017-0709
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
Acceso Abierto
Exocomets: A spectroscopic survey
(EDP Sciences, 2020-07-01) Rebollido, I.; Eiroa, C.; Montesinos Comino, B.; Maldonado, J.; Villaver, E.; Absil, O.; Bayo, A.; Canovas, H.; Carmona, A.; Chen, Ch.; Ertel, E.; Henning, T.; Iglesias, D. P.; Launhardt, R.; Liseau, R.; Meeus, G.; Moór, A.; Mora, A.; Olofsson, J.; Rauw, Gregor; Rivière Marichalar, P.; Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT); Ministerio de Economía y Competitividad (MINECO); 0000-0002-4388-6417; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Context. While exoplanets are now routinely detected, the detection of small bodies in extrasolar systems remains challenging. Since the discovery of sporadic events, which are interpreted to be exocomets (falling evaporating bodies) around β Pic in the early 1980s, only ∼20 stars have been reported to host exocomet-like events. Aims. We aim to expand the sample of known exocomet-host stars, as well as to monitor the hot-gas environment around stars with previously known exocometary activity. Methods. We have obtained high-resolution optical spectra of a heterogeneous sample of 117 main-sequence stars in the spectral type range from B8 to G8. The data were collected in 14 observing campaigns over the course of two years from both hemispheres. We analysed the Ca II K&H and Na I D lines in order to search for non-photospheric absorptions that originated in the circumstellar environment and for variable events that could be caused by the outgassing of exocomet-like bodies. Results. We detected non-photospheric absorptions towards 50% of the sample, thus attributing a circumstellar origin to half of the detections (i.e. 26% of the sample). Hot circumstellar gas was detected in the metallic lines inspected via narrow stable absorptions and/or variable blue- and red-shifted absorption events. Such variable events were found in 18 stars in the Ca II and/or Na I lines; six of them are reported in the context of this work for the first time. In some cases, the variations we report in the Ca II K line are similar to those observed in β Pic. While we do not find a significant trend in the age or location of the stars, we do find that the probability of finding CS gas in stars with larger v sin i is higher. We also find a weak trend with the presence of near-infrared excess and with anomalous (λ Boo-like) abundances, but this would require confirmation by expanding the sample.
Acceso Abierto
The A-shell star ϕ Leo revisited: its photospheric and circumstellar spectra
(EDP Sciences, 2021-09-21) Eiroa, C.; Montesinos Comino, B.; Rebollido, I.; Henning, T.; Launhardt, R.; Maldonado, J.; Meeus, G.; Mora, A.; Rivière Marichalar, P.; Villaver, E.; Agencia Estatal de Investigación (AEI); Ministerio de Economía y Competitividad (MINECO); Istituto Nazionale di Astrofisica (INAF); Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Context. We previously suggested that variable red- and blueshifted absorption features observed in the Ca II K line towards the A-type shell star ϕ Leo are likely due to solid, comet-like bodies in the circumstellar (CS) environment. Aims. Our aim is to expand our observational study of ϕ Leo to other characteristic spectral lines of A-type photospheres as well as to lines arising in their CS shells. Methods. We obtained more than 500 high-resolution optical spectra collected at different telescopes over 37 nights in several observing runs from December 2015 to January 2019. Consecutive time-series spectra were taken, covering intervals of up to ~9 h on some nights. We analysed some photospheric lines, in particular Ca I 4226 Å and Mg II 4481 Å, as well as the circumstellar shell lines Ca II H and K, the Ca II IR triplet, Fe II 4924, 5018, and 5169 Å, Ti II 3685, 3759, and 3761 Å, and the Balmer lines Hα and Hβ. Results. Our observational study reveals that ϕ Leo is a variable δ Scuti star whose spectra show remarkable dumps and bumps superimposed on the photospheric line profiles, which vary in strength and sharpness, propagate from blue- to more redshifted radial velocities, and persist for a few hours. Similarly to other δ Scuti stars, these features are likely produced by non-radial pulsations. At the same time, all shell lines present emission at ~3 km s−1 centred at the core of the CS features, and two variable absorption minima at both sides of the emission; those absorption minima occur at almost the same velocity for each line, that is, no apparent dynamical evolution is observed. The variations observed in the Ca II H and K, Fe II, and Ti II lines occur on a range of timescales from minutes to days and between observing runs, but without any clear correlation or recognisable temporal pattern among the different lines. In the case of Hα, the CS contribution is also variable in just one of the observing runs. Conclusions. We suggest that ϕ Leo is a rapidly rotating δ Scuti star surrounded by a variable, (nearly) edge-on CS disk possibly re-supplied by the δ Scuti pulsations. The behaviour of the CS shell lines is reminiscent of that of rapidly rotating Be shell stars with an edge-on CS disk, and is clear evidence that the variations observed in the CS features of ϕ Leo are highly unlikely to be produced by exocomets. In addition, the observational results presented in this work, together with some recent results concerning the shell star HR 10, highlight the need for critical revision of the Ca II K features, which have been attributed to exocomets in other shell stars.