Examinando por Autor "Schweitzer, A."

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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, E.; Rodríguez, E.; López González, M. J.; Rodríguez López, C.; Cifuentes, C.; Mordasini, C.; Jeffers, S. V.; Rix, H. W.; Ofir, A.; Kürster, M.; Henning, T.; Emsenhuber, A.; Passegger, V. M.; Abellán, F. J.; Rodríguez Trinidad, A.; Pedraz, S.; Aceituno, J.; Seifert, W.; Fernández Martín, A.; Zechmeister, M.; De Juan, E.; Perryman, M. A. C.; Antona, R.; Alonso Floriano, F. J.; Ferro, I. M.; Johnson, E. N.; Labiche, N.; Rebolo, R.; Becerril Jarque, S.; Azzaro, M.; Fuhrmeister, B.; Lizon, J. L.; Perger, M.; Brinkmöller, M.; Berdiñas, Z. M.; Galadí Enríquez, D.; López Santiago, J.; Cortés Contreras, M.; Calvo Ortega, R.; Del Burgo, C.; Gallardo Cava, I.; Rosich, A.; Cardona Guillén, C.; Cano, J.; García Vargas, M. L.; Amado, P. J.; Casanova, V.; Carro, J.; García Piquer, A.; Kaminski, A.; Chaturvedi, P.; Gesa, L.; Abril, M.; Claret, A.; González Álvarez, E.; Ammler von Eiff, M.; Czesla, S.; Barrado, D.; Dorda, R.; González Peinado, R.; Fernández Hernández, Maite; Klüter, J.; Kim, M.; Lara, L. M.; Lampón, M.; López del Fresno, M.; Lodieu, N.; Mancini, L.; Mall, U.; Martín Fernández, P.; Mirabet, E.; Nortmann, L.; Pallé, E.; Caballero, J. A.; Huke, P.; Huber, A.; Holgado, G.; Klutsch, A.; Launhardt, R.; López Salas, F. J.; Stürmer, J.; Suárez, J. C.; Tabernero, H.; Tulloch, S. M.; Veredas, G.; Vico Linares, J. I.; Vilardell, F.; Wagner, K.; Winkler, J.; Wolthoff, V.; Sánchez López, A.; Sánchez Blanco, E.; Sadegi, S.; Labarga, F.; Marfil, E.; Casasayas Barris, N.; Bergond, G.; Martín, E. L.; Mandel, H.; Sarkis, P.; Lázaro, F. J.; Luque, R.; Burn, R.; Marvin, E. L.; Martín Ruiz, S.; Sarmiento, L. F.; González Cuesta, L.; Anglada Escudé, G.; Cárdenas, M. C.; Nelson, R. P.; Moya, A.; Schäfer, S.; Reffert, S.; Casal, E.; Pascual, J.; Nowak, G.; Schlecker, M.; Quirrenbach, A.; Kemmer, J.; Pérez Medialdea, D.; Pavlov, A.; Schmitt, J. H. M. M.; Lalitha, S.; Rabaza, O.; Pérez Calpena, A.; Schöfer, P.; Llamas, M.; Redondo, P.; Ramón Ballesta, A.; Magán Madinabeitia, H.; Rodler, F.; Sota, A.; Marín Molina, J. A.; Sabotta, S.; Stahl, O.; Martínez Rodríguez, H.; Salz, M.; Stock, S.; Naranjo, V.; Sánchez Carrasco, M. A.; Stuber, T.; Sanz Forcada, J.; Johansen, A.; Baroch, D.; Lafarga, M.; Dreizler, S.; Tal Or, L.; Schweitzer, A.; Hagen, H. J.; Guenther, E. W.; Montes, D.; Aceituno, Francisco José; Arroyo Torres, B.; Benítez, D.; Kehr, M.; Béjar, V. J. S.; Zapatero Osorio, M. R.; Yan, F.; Klahr, H.; Nagel, E.; Trifonov, T.; Guàrdia, J.; Guijarro, A.; De Guindos, E.; Hatzes, A. P.; Hauschildt, P. H.; Hedrosa, R. P.; Hermelo, I.; Hernández Arabi, R.; Hernández Otero, F.; Hintz, D.; Díez Alonso, E.; Colomé, J.; González Hernández, Carmen; Solano, Enrique; 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]; Luque, R. [0000-0002-4671-2957]; López Santiago, J. [0000-0003-2402-8166]; Perger, M. [0000-0001-7098-0372]; Guenther, E. W. [0000-0002-9130-6747]; Schmitt, J. H. M. M. [0000-0003-2554-9916]; Mordasini, C. [0000-0002-1013-2811]; Aceituno, J. [0000-0003-0487-1105]; Stock, S. [0000-0002-1166-9338]; Lafarga, M. [0000-0002-8815-9416]; Nagel, E. [0000-0002-4019-3631]; Barrado, D. [0000-0002-5971-9242]; Tulloch, S. [0000-0003-0840-8521]; Rosich, A. [0000-0002-9141-3067]; Trifonov, T. [0000-0002-0236-775X]; Bergond, G. [0000-0003-3132-9215]; Zapatero Osorio, M. R. [0000-0001-5664-2852]; Kaminski, A. [0000-0003-0203-8208]; Montes, D. [0000-0002-7779-238X]; Cano, J. [0000-0003-1984-5401]; Baroch, D. [0000-0001-7568-5161]; Alonso Floriano, F. J. [0000-0003-1202-5734]; Sabotta, S. [0000-0001-9078-5574]; Ammler-von Eiff, M. [0000-0001-9565-1698]; Chaturvedi, P. [0000-0002-1887-1192]; Anglada Escudé, G. [0000-0002-3645-5977]; Becerril Jarque, S. [0000-0001-9009-1150]; Díez Alonso, E. [0000-0002-5826-9892]; Passegger, V. M. [0000-0002-8569-7243]; Burn, R. [0000-0002-9020-7309]; García Vargas, M. L. [0000-0002-2058-3528]; Amado, P. J. [0000-0002-8388-6040]; Cardona Guillén, C. [0000-0002-2198-4200]; Carro, J. [0000-0002-0838-3603]; Guàrdia, J. [0000-0002-7191-9001]; Abellán, F. J. [0000-0002-5724-1636]; Cifuentes, C. [0000-0003-1715-5087]; Colomé, J. [0000-0002-1678-2241]; Hermelo, I. [0000-0001-9178-694X]; Arroyo Torres, B. [0000-0002-3392-4694]; Emsenhuber, A. [0000-0002-8811-1914]; Fuhrmeister, B. [0000-0001-8321-5514]; Johnson, E. [0000-0003-2260-5134]; Berdiñas, Z. M. [0000-0002-6057-6461]; González Álvarez, E. [0000-0002-4820-2053]; González Cuesta, L. [0000-0002-1241-5508]; González Hernández, J. I. [0000-0002-0264-7356]; Klüter, J. [0000-0002-3469-5133]; Calvo Ortega, R. [0000-0003-3693-6030]; Guijarro, A. [0000-0001-5518-1759]; Lara, L. M. [0000-0002-7184-920X]; Casasayas Barris, N. [0000-0002-2891-8222]; Hintz, D. [0000-0002-5274-2589]; López del Fresno, M. [0000-0002-9479-7780]; Czesla, S. [0000-0002-4203-4773]; De Juan Fernández, E. [0000-0002-9382-4505]; Kehr, M. [0000-0002-7420-7368]; Marín Molina, J. A. [0000-0002-3525-0806]; Galadí Enríquez, D. [0000-0003-4946-5653]; Klutsch, A. [0000-0001-7869-3888]; Labarga, F. [0000-0002-7143-0206]; Martínez Rodríguez, H. [0000-0002-1919-228X]; González Peinado, R. [0000-0002-6658-8930]; Launhardt, R. [0000-0002-8298-2663]; Lizon, J. L. [0000-0001-8928-2566]; Naranjo, V. [0000-0003-0097-1061]; De Guindos, E. [0000-0002-8124-9101]; Magan Madinabeitia, H. [0000-0003-1243-4597]; Aceituno, F. J. [0000-0001-8074-4760]; Manici, L. [0000-0002-9428-8732]; Ofir, A. [0000-0002-9152-5042]; Huke, P. [0000-0001-5913-2743]; Martín, E. [0000-0002-1208-4833]; Rabaza, O. [0000-0003-2766-2103]; Kim, M. [0000-0001-6218-2004]; Marvin, C. J. [0000-0002-2249-2611]; Rodríguez Trinidad, A. [0000-0002-3356-8634]; Lampón, M. [0000-0002-0183-7158]; Nelson, R. [0000-0002-9687-8779]; Nortmann, L. [0000-0001-8419-8760]; Sanz Forcada, J. [0000-0002-1600-7835]; Lodieu, N. [0000-0002-3612-8968]; Pascual Granado, J. [0000-0003-0139-6951]; Pedraz, S. [0000-0003-1346-208X]; Schäfer, S. [0000-0001-8597-8048]; Marfil, E. [0000-0001-8907-4775]; Ramón Ballesta, A. [0000-0002-4323-0610]; Redondo, P. G. [0000-0001-5992-5778]; Schöfer, P. [0000-0002-5969-3708]; Martín Ruiz, S. [0000-0002-9006-7182]; Sadegi, S. [0000-0001-9897-6121]; García Piquer, A. [0000-0002-6872-4262]; Sánchez Carrasco, M. A. [0000-0001-5533-3660]; Stuber, T. [0000-0003-2185-0525]; Moya, A. [0000-0003-1665-5389]; Sarkis, P. [0000-0001-8128-3126]; Vilardell, F. [0000-0003-0441-1504]; Nowak, G. [0000-0002-7031-7754]; Schlecker, M. [0000-0001-8355-2107]; Béjar, V. J. S. [0000-0002-5086-4232]; Pérez Calpena, A. [0000-0001-7361-9240]; Solano, E. [0000-0003-1885-5130]; Sota, A. [https://orcid.org/0000-0002-9404-6952]; Klahr, H. [0000-0002-8227-5467]; Rodler, F. [0000-0003-0650-5723]; Suárez, J. C. [0000-0003-3649-8384]; Tabernero, H. [0000-0002-8087-4298]; Cortés Contreras, M. [0000-0003-3734-9866]; Sánchez López, A. [0000-0002-0516-7956]; Winkler, J. [0000-0003-0568-8820]; Yan, F. [0000-0001-9585-9034]; Reffert, S. [0000-0002-0460-8289]; Sarmiento, L. F. [0000-0002-8475-9705]; 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
A He I upper atmosphere around the warm Neptune GJ 3470 b
(EDP Sciences, 2020-06-11) Pallé, E.; Nortmann, L.; Casasayas Barris, N.; Lampón, M.; López Puertas, M.; Caballero, J. A.; Sanz Forcada, J.; Lara, L. M.; Nagel, E.; Yan, F.; Alonso Floriano, F. J.; Amado, P. J.; Chen, G.; Cifuentes, C.; Cortés Contreras, M.; Czesla, S.; Molaverdikhani, K.; Montes, D.; Passegger, V. M.; Quirrenbach, A.; Reiners, A.; Ribas, I.; Sánchez López, A.; Schweitzer, A.; Strangret, M.; Zapatero Osorio, M. R.; Zechmeister, M.; Agencia Estatal de Investigación (AEI); Ministerio de Economía y Competitividad (MINECO); National Natural Science Foundation of China (NSFC); 0000-0003-0987-1593; 0000-0002-2891-8222; 0000-0003-2941-7734; 0000-0002-7349-1387; 0000-0003-3734-9866; 0000-0001-5664-2852; 0000-0002-6532-4378; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
High resolution transit spectroscopy has proven to be a reliable technique for the characterization of the chemical composition of exoplanet atmospheres. Taking advantage of the broad spectral coverage of the CARMENES spectrograph, we initiated a survey aimed at characterizing a broad range of planetary systems. Here, we report our observations of three transits of GJ 3470 b with CARMENES in search of He (2(3)S) absorption. On one of the nights, the He & x202f;Iregion was heavily contaminated by OH(-)telluric emission and, thus, it was not useful for our purposes. The remaining two nights had a very different signal-to-noise ratio (S/N) due to weather. They both indicate the presence of He (2(3)S) absorption in the transmission spectrum of GJ 3470 b, although a statistically valid detection can only be claimed for the night with higher S/N. For that night, we retrieved a 1.5 +/- 0.3% absorption depth, translating into aR(p)(lambda)/R-p= 1.15 +/- 0.14 at this wavelength. Spectro-photometric light curves for this same night also indicate the presence of extra absorption during the planetary transit with a consistent absorption depth. The He (2(3)S) absorption is modeled in detail using a radiative transfer code, and the results of our modeling efforts are compared to the observations. We find that the mass-loss rate,& x1e40;, is confined to a range of 3 x 10(10)g s(-1)forT= 6000 K to 10 x 10(10)g s(-1)forT= 9000 K. We discuss the physical mechanisms and implications of the He & x202f;Idetection in GJ 3470 b and put it in context as compared to similar detections and non-detections in other Neptune-size planets. We also present improved stellar and planetary parameter determinations based on our visible and near-infrared observations. © ESO 2020.
Restringido
A nearby transiting rocky exoplanet that is suitable for atmospheric investigation
(Science, 2021-03-05) Trifonov, T.; Caballero, J. A.; Morales, J. C.; Seifahrt, A.; Reiners, A.; Bean, J. L.; Luque, R.; Parviainen, H.; Pallé, E.; Stock, S.; Zechmeister, M.; Amado, P. J.; Anglada Escudé, G.; Azzaro, M.; Barclay, T.; Béjar, V. J. S.; Bluhm, P.; Casasayas Barris, N.; Cifuentes, C.; Collins, K. A.; Collins, K. I.; Cortés Contreras, M.; De Leon, J. P.; Dreizler, S.; Dressing, C. D.; Esparza Borges, E.; Espinoza, N.; Fausnaugh, M.; Fukui, A.; Hatzes, A. P.; Hellier, C.; Henning, T.; Henze, C. E.; Herrero, E.; Jeffers, S. V.; Jenkins, J. M.; Jensen, E. L. N.; Kaminski, A.; Kasper, D.; Kossakowski, D.; Kürster, M.; Lafarga, M.; Latham, D. W.; Mann, A. W.; Molaverdikhani, K.; Montes, D.; Montet, B. T.; Murgas Alcaino, F.; Narita, N.; Oshagh, M.; Passegger, V. M.; Pollacco, D.; Quinn, S. N.; Quirrenbach, A.; Ricker, G. R.; Rodríguez López, C.; Sánz Forcada, J.; Schwarz, R. P.; Schweitzer, A.; Seager, S.; Shporer, A.; Stangret, M.; Stürmer, J.; Tan, T. G.; Tenenbaum, P.; Twicken, J. D.; Vanderspek, R.; Winn, J. N.; Deutsche Forschungsgemeinschaft (DFG); Agencia Estatal de Investigación (AEI); National Aeronautics and Space Administration (NASA); European Research Council (ERC); Japan Society for the Promotion of Science (JSPS); La Caixa; Japan Science and Technology Agency (JST); Trifonov, T. [0000-0002-0236-775X]; Caballero, J. A. [0000-0002-7349-1387]; Morales, J. C. [0000-0003-0061-518X]; Seifahrt, A. [0000-0003-4526-3747]; Ribas, I. [0000-0002-6689-0312]; Bean, J. [0000-0003-4733-6532]; Luque, R. [0000-0002-4671-2957]; Parviainen, H. [0000-0001-5519-1391]; Pallé, E. [0000-0003-0987-1593]; Stock, S. [0000-0002-1166-9338]; Zechmeister, M. [0000-0002-6532-4378]; Amado, P. J. [0000-0002-8388-6040]; Anglada Escudé, G. [0000-0002-3645-5977]; Azzaro, M. [0000-0002-1317-0661]; Barclay, T. [0000-0001-7139-2724]; Béjar, V. J. S. [0000-0002-5086-4232]; Bluhm, P. [0000-0002-0374-8466]; Casasayas Barris, N. [0000-0002-2891-8222]; Cifuentes, C. [0000-0003-1715-5087]; Collins, K. A. [0000-0001-6588-9574]; Collins, K. I. [0000-0003-2781-3207]; Cortés Contreras, M. [0000-0003-3734-9866]; Dreizler, S. [0000-0001-6187-5941]; Dressing, C. D. [0000-0001-8189-0233]; Esparza Borges, E. [0000-0002-2341-3233]; Espinoza, N. [0000-0001-9513-1449]; Fausnaugh, M. [0000-0002-9113-7162]; Fukui, A. [0000-0002-4909-5763]; Hatzes, A. P. [0000-0002-3404-8358]; Hellier, C. [0000-0002-3439-1439]; Henning, T. [0000-0002-1493-300X]; Herrero, E. [0000-0001-8602-6639]; Jeffers, S. V. [0000-0003-2490-4779]; Jenkins, J. M. [0000-0002-4715-9460]; Jensen, E. L. N. [0000-0002-4625-7333]; Kaminski, A. [0000-0003-0203-8208]; Kasper, D. [0000-0003-0534-6388]; Kossakowski, D. [0000-0002-0436-7833]; Lafarga, M. [0000-0002-8815-9416]; Latham, D. W. [0000-0001-9911-7388]; Mann, A. W. [0000-0003-3654-1602]; Molaverdikhani, K. [0000-0002-0502-0428]; Montes, D. [0000-0002-7779-238X]; Montet, B. T. [0000-0001-7516-8308]; Murgas, F. [0000-0001-9087-1245]; Narita, N. [0000-0001-8511-2981]; Oshagh, M. [0000-0002-0715-8789]; Passegger, V. M. [0000-0002-8569-7243]; Pollacco, D. [0000-0001-9850-9697]; Quinn, S. N. [0000-0002-8964-8377]; Rodríguez López, C. [0000-0001-5559-7850]; Sanz Forcada, J. [0000-0002-1600-7835]; Schwarz, R. P. [0000-0001-8227-1020]; Schweitzer, A. [0000-0002-1624-0389]; Seager, S. [0000-0002-6892-6948]; Stangret, M. [0000-0002-1812-8024]; Stürmer, J. [0000-0002-4410-4712]; Tan, T. G. [0000-0001-5603-6895]; Tenenbaum, P. [0000-0002-1949-4720]; Twicken, J. D. [0000-0002-6778-7552]; Vanderspek, R. [0000-0001-6763-6562]; Winn, J. N. [0000-0002-4265-047X]; Centros de Excelencia Severo Ochoa, INSTITUTO DE ASTROFISICA DE ANDALUCIA (IAA), SEV-2017-0709; Centros de Excelencia Severo Ochoa, INSTITUTO DE ASTROFÍSICA DE CANARIAS (IAC), SEV-2015-0548; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Spectroscopy of transiting exoplanets can be used to investigate their atmospheric properties and habitability. Combining radial velocity (RV) and transit data provides additional information on exoplanet physical properties. We detect a transiting rocky planet with an orbital period of 1.467 days around the nearby red dwarf star Gliese 486. The planet Gliese 486 b is 2.81 Earth masses and 1.31 Earth radii, with uncertainties of 5%, as determined from RV data and photometric light curves. The host star is at a distance of ~8.1 parsecs, has a J-band magnitude of ~7.2, and is observable from both hemispheres of Earth. On the basis of these properties and the planet’s short orbital period and high equilibrium temperature, we show that this terrestrial planet is suitable for emission and transit spectroscopy.
Acceso Abierto
CARMENES input catalogue of M dwarfs: V. Luminosities, colours, and spectral energy distributions
(EDP Sciences, 2020-10-12) Cifuentes, C.; Caballero, J. A.; Cortés Contreras, M.; Montes, D.; Abellán, F. J.; Dorda, R.; Holgado, G.; Zapatero Osorio, M. R.; Morales, J. C.; Amado, P. J.; Passegger, V. M.; Quirrenbach, A.; Reiners, A.; Ribas, I.; Sanz Forcada, J.; Schweitzer, A.; Seifert, W.; Solano, Enrique; Agencia Estatal de Investigación (AEI); National Aeronautics and Space Administration (NASA); 0000-0003-1715-5087; 0000-0002-7349-1387; 0000-0003-3734-9866; 0000-0002-7779-238X; 0000-0001-5664-2852; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Context. The relevance of M dwarfs in the search for potentially habitable Earth-sized planets has grown significantly in the last years. Aims. In our on-going effort to comprehensively and accurately characterise confirmed and potential planet-hosting M dwarfs, in particular for the CARMENES survey, we have carried out a comprehensive multi-band photometric analysis involving spectral energy distributions, luminosities, absolute magnitudes, colours, and spectral types, from which we have derived basic astrophysical parameters. Methods. We have carefully compiled photometry in 20 passbands from the ultraviolet to the mid-infrared, and combined it with the latest parallactic distances and close-multiplicity information, mostly from Gaia DR2, of a sample of 2479 K5 V to L8 stars and ultracool dwarfs, including 2210 nearby, bright M dwarfs. For this, we made extensive use of Virtual Observatory tools. Results. We have homogeneously computed accurate bolometric luminosities and effective temperatures of 1843 single stars, derived their radii and masses, studied the impact of metallicity, and compared our results with the literature. The over 40 000 individually inspected magnitudes, together with the basic data and derived parameters of the stars, individual and averaged by spectral type, have been made public to the astronomical community. In addition, we have reported 40 new close multiple systems and candidates (ρ < 3.3 arcsec) and 36 overluminous stars that are assigned to young Galactic populations. Conclusions. In the new era of exoplanet searches around M dwarfs via transit (e.g. TESS, PLATO) and radial velocity (e.g. CARMENES, NIRPS+HARPS), this work is of fundamental importance for stellar and therefore planetary parameter determination. © ESO 2020.
Acceso Abierto
Mass and density of the transiting hot and rocky super-Earth LHS 1478 b (TOI-1640 b)
(EDP Sciences, 2021-05-21) Soto, M. G.; Anglada Escudé, G.; Dreizler, S.; Molaverdikhani, K.; Kemmer, J.; Rodríguez López, C.; Lillo Box, J.; Pallé, E.; Espinoza, N.; Caballero, J. A.; Quirrenbach, A.; Ribas, I.; Reiners, A.; Narita, N.; Hirano, T.; Amado, P. J.; Béjar, V. J. S.; Bluhm, P.; Burke, C. J.; Caldwell, D. A.; Charbonneau, D.; Cloutier, R.; Collins, K. A.; Cortés Contreras, M.; Girardin, E.; Guerra, P.; Harakawa, H.; Hatzes, A. P.; Irwin, J.; Jenkins, J. M.; Jensen, E.; Kawauchi, K.; Kotani, T.; Kudo, T.; Kunimoto, M.; Kuzuhara, M.; Latham, D. W.; Montes, D.; Morales, J. C.; Mori, M.; Nelson, R. P.; Omiya, M.; Pedraz, S.; Passegger, V. M.; Rackham, B. V.; Rudat, A.; Schlieder, J. E.; Schöfer, P.; Schweitzer, A.; Selezneva, A.; Stockdale, C.; Tamura, M.; Trifonov, T.; Vanderspek, R.; Watanabe, N.; Deutsche Forschungsgemeinschaft (DFG); Ministerio de Economía y Competitividad (MINECO); Junta de Andalucía; Science and Technology Facilities Council (STFC); National Aeronautics and Space Administration (NASA); Agencia Estatal de Investigación (AEI); Generalitat de Catalunya; Japan Society for the Promotion of Science (JSPS); Soto, M. G. [0000-0001-9743-5649]; Centros de Excelencia Severo Ochoa, INSTITUTO DE ASTROFÍSICA DE CANARIAS (IAC), SEV-2015-0548; Centros de Excelencia Severo Ochoa, INSTITUTO DE ASTROFISICA DE ANDALUCIA (IAA), SEV-2017-0709; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
One of the main objectives of the Transiting Exoplanet Survey Satellite (TESS) mission is the discovery of small rocky planets around relatively bright nearby stars. Here, we report the discovery and characterization of the transiting super-Earth planet orbiting LHS 1478 (TOI-1640). The star is an inactive red dwarf (J ~ 9.6 mag and spectral type m3 V) with mass and radius estimates of 0.20 ± 0.01M⊙ and 0.25 ± 0.01R⊙, respectively, and an effective temperature of 3381 ± 54 K. It was observed by TESS in four sectors. These data revealed a transit-like feature with a period of 1.949 days. We combined the TESS data with three ground-based transit measurements, 57 radial velocity (RV) measurements from CARMENES, and 13 RV measurements from IRD, determining that the signal is produced by a planet with a mass of 2.33−0.20+0.20 M⊕ and a radius of 1.24−0.05+0.05 R⊕. The resulting bulk density of this planet is 6.67 g cm−3, which is consistent with a rocky planet with an Fe- and MgSiO3-dominated composition. Although the planet would be too hot to sustain liquid water on its surface (its equilibrium temperature is about ~595 K, suggesting aVenus-like atmosphere), spectroscopic metrics based on the capabilities of the forthcoming James Webb Space Telescope and the fact that the host star is rather inactive indicate that this is one of the most favorable known rocky exoplanets for atmospheric characterization.
Acceso Abierto
The CARMENES search for exoplanets around M dwarfs A deep learning approach to determine fundamental parameters of target stars
(EDP Sciences, 2020-09-30) Passegger, V. M.; Bello García, A.; Ordieres Meré, J.; Caballero, J. A.; Schweitzer, A.; González Marcos, A.; Ribas, I.; Reiners, A.; Quirrenbach, A.; Amado, P. J.; Azzaro, M.; Bauer, F. F.; Béjar, V. J. S.; Cortés Contreras, M.; Dreizler, S.; Hatzes, A. P.; Henning, T.; Jeffers, S. V.; Kaminski, A.; Kürster, M.; Lafarga, M.; Marfil, E.; Montes, D.; Morales, J. C.; Nagel, E.; Sarro, L. M.; Tabernero, H. M.; Zechmeister, M.; Solano, Enrique; Agencia Estatal de Investigación (AEI); Fundacao para a Ciencia e a Tecnologia (FCT); National Aeronautics and Space Administration (NASA); Bello García, A. [0000-0001-8691-3342]; Ordieres Meré, J. [0000-0002-9677-6764]; Caballero, J. A. [0000-0002-7349-1387]; González Marcos, A. [0000-0003-4684-659X]; Ribas, I. [0000-0002-6689-0312]; Azzaro, M. [0000-0002-1317-0661]; Kürster, M. [0000-0002-1765-9907]; Marfil, E. [0000-0001-8907-4775]; Montes, D. [0000-0002-7779-238X]; Morales, J. C. [0000-0003-0061-518X]; Nagel, E. [0000-0002-4019-3631]; Sarro, L. M. [0000-0002-5622-5191]; Tabernero, H. [0000-0002-8087-4298]; Zechmesister, M. [0000-0002-6532-4378]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Existing and upcoming instrumentation is collecting large amounts of astrophysical data, which require efficient and fast analysis techniques. We present a deep neural network architecture to analyze high-resolution stellar spectra and predict stellar parameters such as effective temperature, surface gravity, metallicity, and rotational velocity. With this study, we firstly demonstrate the capability of deep neural networks to precisely recover stellar parameters from a synthetic training set. Secondly, we analyze the application of this method to observed spectra and the impact of the synthetic gap (i.e., the difference between observed and synthetic spectra) on the estimation of stellar parameters, their errors, and their precision. Our convolutional network is trained on synthetic PHOENIX-ACES spectra in different optical and near-infrared wavelength regions. For each of the four stellar parameters, Teff, log g, [M/H], and v sin i, we constructed a neural network model to estimate each parameter independently. We then applied this method to 50 M dwarfs with high-resolution spectra taken with CARMENES (Calar Alto high-Resolution search for M dwarfs with Exo-earths with Near-infrared and optical Échelle Spectrographs), which operates in the visible (520–960 nm) and near-infrared wavelength range (960–1710 nm) simultaneously. Our results are compared with literature values for these stars. They show mostly good agreement within the errors, but also exhibit large deviations in some cases, especially for [M/H], pointing out the importance of a better understanding of the synthetic gap.
Acceso Abierto
The CARMENES search for exoplanets around M dwarfs Convective shift and starspot constraints from chromatic radial velocities
(EDP Sciences, 2020-09-10) Baroch, D.; Morales, J. C.; Ribas, I.; Herrero, E.; Rosich, A.; Perger, M.; Anglada Escudé, G.; Reiners, A.; Caballero, J. A.; Quirrenbach, A.; Amado, P. J.; Jeffers, S. V.; Cifuentes, C.; Passegger, V. M.; Schweitzer, A.; Lafarga, M.; Bauer, F. F.; Béjar, V. J. S.; Colomé, J.; Cortés Contreras, M.; Dreizler, S.; Galadí Enríquez, D.; Hatzes, A. P.; Henning, T.; Kaminski, A.; Kürster, M.; Montes, D.; Rodríguez López, C.; Zechmeister, M.; Deutsche Forschungsgemeinschaft (DFG); Agencia Estatal de Investigación (AEI); National Aeronautics and Space Administration (NASA); Baroch, D. [0000-0001-7568-5161]; Ribas, I. [0000-0002-6689-0312]; Montes, D. [0000-0002-7779-238X]; 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 ASTROFÍSICA DE CANARIAS (IAC), SEV-2015-0548; Centros de Excelencia Severo Ochoa, INSTITUTO DE ASTROFISICA DE ANDALUCIA (IAA), SEV-2017-0709
Context. Variability caused by stellar activity represents a challenge to the discovery and characterization of terrestrial exoplanets and complicates the interpretation of atmospheric planetary signals. Aims. We aim to use a detailed modeling tool to reproduce the effect of active regions on radial velocity measurements, which aids the identification of the key parameters that have an impact on the induced variability. Methods. We analyzed the effect of stellar activity on radial velocities as a function of wavelength by simulating the impact of the properties of spots, shifts induced by convective motions, and rotation. We focused our modeling effort on the active star YZ CMi (GJ 285), which was photometrically and spectroscopically monitored with CARMENES and the Telescopi Joan Oró. Results. We demonstrate that radial velocity curves at different wavelengths yield determinations of key properties of active regions, including spot-filling factor, temperature contrast, and location, thus solving the degeneracy between them. Most notably, our model is also sensitive to convective motions. Results indicate a reduced convective shift for M dwarfs when compared to solar-type stars (in agreement with theoretical extrapolations) and points to a small global convective redshift instead of blueshift. Conclusions. Using a novel approach based on simultaneous chromatic radial velocities and light curves, we can set strong constraints on stellar activity, including an elusive parameter such as the net convective motion effect.
Acceso Abierto
The CARMENES search for exoplanets around M dwarfs Different roads to radii and masses of the target stars
(EDP Sciences, 2019-05-14) Schweitzer, A.; Passegger, V. M.; Cifuentes, C.; Béjar, V. J. S.; Cortés Contreras, M.; Caballero, J. A.; Del Burgo, C.; Czesla, S.; Kürster, M.; Montes, D.; Zapatero Osorio, M. R.; Ribas, I.; Reiners, A.; Quirrenbach, A.; Amado, P. J.; Aceituno, J.; Anglada Escudé, G.; Bauer, F. F.; Dreizler, S.; Jeffers, S. V.; Guenther, E. W.; Henning, T.; Kaminski, A.; Lafarga, M.; Marfil, E.; Morales, J. C.; Schmitt, J. H. M. M.; Seifert, W.; Tabernero, H. M.; Zechmeister, M.; Solano, Enrique; Agencia Estatal de Investigación (AEI); Ministerio de Economía y Competitividad (MINECO); Deutsche Forschungsgemeinschaft (DFG); 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
Aims. We determine the radii and masses of 293 nearby, bright M dwarfs of the CARMENES survey. This is the first time that such a large and homogeneous high-resolution (R > 80 000) spectroscopic survey has been used to derive these fundamental stellar parameters. Methods. We derived the radii using Stefan–Boltzmann’s law. We obtained the required effective temperatures Teff from a spectral analysis and we obtained the required luminosities L from integrated broadband photometry together with the Gaia DR2 parallaxes. The mass was then determined using a mass-radius relation that we derived from eclipsing binaries known in the literature. We compared this method with three other methods: (1) We calculated the mass from the radius and the surface gravity log g, which was obtained from the same spectral analysis as Teff. (2) We used a widely used infrared mass-magnitude relation. (3) We used a Bayesian approach to infer stellar parameters from the comparison of the absolute magnitudes and colors of our targets with evolutionary models. Results. Between spectral types M0 V and M7 V our radii cover the range 0.1 R⊙ < R < 0.6 R⊙ with an error of 2–3% and our masses cover 0.09 ℳ⊙ < ℳ< 0.6ℳ⊙ with an error of 3–5%. We find good agreement between the masses determined with these different methods for most of our targets. Only the masses of very young objects show discrepancies. This can be well explained with the assumptions that we used for our methods.
Acceso Abierto
The CARMENES search for exoplanets around M dwarfs No evidence for a super-Earth in a 2-day orbit around GJ 1151
(EDP Sciences, 2021-05-07) Perger, M.; Ribas, I.; Anglada Escudé, G.; Morales, J. C.; Amado, P. J.; Caballero, J. A.; Quirrenbach, A.; Reiners, A.; Béjar, V. J. S.; Dreizler, S.; Galadí Enríquez, D.; Hatzes, A. P.; Henning, T.; Jeffers, S. V.; Kaminski, A.; Kürster, M.; Lafarga, M.; Montes, D.; Pallé, E.; Rodríguez López, C.; Schweitzer, A.; Zapatero Osorio, M. R.; Zechmeister, M.; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MINECO/ICTI2013-2016/MDM-2017-0737; Perger, M. [0000-0001-7098-0372]; Montes, D. [0000-0002-7779-238X]; Centros de Excelencia Severo Ochoa, INSTITUTO DE ASTROFÍSICA DE CANARIAS (IAC), SEV-2015-0548; Centros de Excelencia Severo Ochoa, INSTITUTO DE ASTROFISICA DE ANDALUCIA (IAA), SEV-2017-0709; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Context. The interaction between Earth-like exoplanets and the magnetic field of low-mass host stars are considered to produce weak emission signals at radio frequencies. A study using LOFAR data announced the detection of radio emission from the mid M-type dwarf GJ 1151 that could potentially arise from a close-in terrestrial planet. Recently, the presence of a 2.5-M⊕ planet orbiting GJ 1151 with a 2-day period has been claimed using 69 radial velocities (RVs) from the HARPS-N and HPF instruments. Aims. We have obtained 70 new high-precision RV measurements in the framework of the CARMENES M-dwarf survey and use these data to confirm the presence of the claimed planet and to place limits on possible planetary companions in the GJ 1151 system. Methods. We analysed the periodicities present in the combined RV data sets from all three instruments and calculated the detection limits for potential planets in short-period orbits. Results. We cannot confirm the recently announced candidate planet and conclude that the 2-day signal in the HARPS-N and HPF data sets is most probably produced by a long-term RV variability, possibly arising from an outer planetary companion that has yet to be constrained. We calculate a 99.9% significance detection limit of 1.50 m s−1 in the RV semi-amplitude, which places upper limits of 0.7 M⊕ and 1.2 M⊕ on the minimum masses of potential exoplanets with orbital periods of 1 and 5 days, respectively.
Desconocido
The CARMENES search for exoplanets around M dwarfs Photospheric parameters of target stars from high-resolution spectroscopy. II. Simultaneous multiwavelength range modeling of activity insensitive lines
(EDP Sciences, 2019-07-17) Passegger, V. M.; Schweitzer, A.; Shulyak, D.; Nagel, E.; Hauschildt, P. H.; Reiners, A.; Amado, P. J.; Caballero, J. A.; Cortés Contreras, M.; Domínguez Fernández, A. J.; Quirrenbach, A.; Ribas, I.; Azzaro, M.; Anglada Escudé, G.; Bauer, F. F.; Béjar, V. J. S.; Dreizler, S.; Guenther, E. W.; Henning, T.; Jeffers, S. V.; Kaminski, A.; Kürster, M.; Lafarga, M.; Martín, E. L.; Montes, D.; Morales, J. C.; Schmitt, J. H. M. M.; Zechmeister, M.; Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI); Deutsche Forschungsgemeinschaft (DFG); Nvidia; 0000-0002-8388-6040; 0000-0003-3734-9866; Centros de Excelencia Severo Ochoa, INSTITUTO DE ASTROFÍSICA DE CANARIAS (IAC), SEV-2015-0548; Centros de Excelencia Severo Ochoa, INSTITUTO DE ASTROFISICA DE ANDALUCIA (IAA), SEV-2017-0709; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
We present precise photospheric parameters of 282 M dwarfs determined from fitting the most recent version of PHOENIX models to high-resolution CARMENES spectra in the visible (0.52–0.96 μm) and NIR wavelength range (0.96–1.71 μm). With its aim to search for habitable planets around M dwarfs, several planets of different masses have been detected. The characterization of the target sample is important for the ability to derive and constrain the physical properties of any planetary systems that are detected. As a continuation of previous work in this context, we derived the fundamental stellar parameters effective temperature, surface gravity, and metallicity of the CARMENES M-dwarf targets from PHOENIX model fits using a χ2 method. We calculated updated PHOENIX stellar atmosphere models that include a new equation of state to especially account for spectral features of low-temperature stellar atmospheres as well as new atomic and molecular line lists. We show the importance of selecting magnetically insensitive lines for fitting to avoid effects of stellar activity in the line profiles. For the first time, we directly compare stellar parameters derived from multiwavelength range spectra, simultaneously observed for the same star. In comparison with literature values we show that fundamental parameters derived from visible spectra and visible and NIR spectra combined are in better agreement than those derived from the same spectra in the NIR alone.
Acceso Abierto
The CARMENES search for exoplanets around M dwarfs Three temperate-to-warm super-Earths
(EDP Sciences, 2020-11-10) Stock, S.; Nagel, E.; Kemmer, J.; Passegger, V. M.; Reffert, S.; Quirrenbach, A.; Caballero, J. A.; Czesla, S.; Béjar, V. J. S.; Cardona Guillén, C.; Díez Alonso, E.; Herrero, E.; Lalitha, S.; Schlecker, M.; Tal Or, L.; Rodríguez, E.; Rodríguez López, C.; Ribas, I.; Reiners, A.; Amado, P. J.; Bauer, F. F.; Bluhm, P.; Cortés Contreras, M.; González Cuesta, L.; Dreizler, S.; Hatzes, A. P.; Henning, T.; Jeffers, S. V.; Kaminski, A.; Kürster, M.; Lafarga, M.; López González, M. J.; Montes, D.; Morales, J. C.; Pedraz, S.; Schöfer, P.; Schweitzer, A.; Trifonov, T.; Zapatero Osorio, M. R.; Zechmeister, M.; Agencia Estatal de Investigación (AEI); Generalitat de Catalunya; National Aeronautics and Space Administration (NASA); Tel-Aviv University (Israel); Stock, S. [0000-0002-1166-9338]; Nagel, E. [0000-0002-4019-3631]; Kemmer, J. [0000-0003-3929-1442]; Reffert, S. [0000-0002-0460-8289]; Caballero, J. A. [0000-0002-7349-1387]; Cardona, C. [0000-0002-2198-4200]; Schlecker, M. [0000-0001-8355-2107]; Tal Or, L. [0000-0003-3757-1440]; Rodríguez, E. [0000-0001-6827-9077]; Ribas, I. [0000-0002-6689-0312]; Amado, P. J. [0000-0002-8388-6040]; Cortés Contreras, M. [0000-0003-3734-9866]; González Cuesta, L. [0000-0002-1241-5508]; López González, M. J. [0000-0001-8104-5128]; Zapatero Osorio, M. R. [0000-0001-5664-2852]; Zechmeister, M. [0000-0002-6532-4378]; 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; Centros de Excelencia Severo Ochoa, INSTITUTO DE ASTROFÍSICA DE CANARIAS (IAC), SEV-2015-0548
We announce the discovery of two planets orbiting the M dwarfs GJ 251 (0.360 ± 0.015M⊙) and HD 238090 (0.578 ± 0.021M⊙) based on CARMENES radial velocity (RV) data. In addition, we independently confirm with CARMENES data the existence of Lalande 21185 b, a planet that has recently been discovered with the SOPHIE spectrograph. All three planets belong to the class of warm or temperate super-Earths and share similar properties. The orbital periods are 14.24 d, 13.67 d, and 12.95 d and the minimum masses are 4.0 ± 0.4 M⊕, 6.9 ± 0.9 M⊕, and 2.7 ± 0.3 M⊕ for GJ 251 b, HD 238090 b, and Lalande 21185 b, respectively. Based on the orbital and stellar properties, we estimate equilibrium temperatures of 351.0 ± 1.4 K for GJ 251 b, 469.6 ± 2.6 K for HD 238090 b, and 370.1 ± 6.8 K for Lalande 21185 b. For the latter we resolve the daily aliases that were present in the SOPHIE data and that hindered an unambiguous determination of the orbital period. We find no significant signals in any of our spectral activity indicators at the planetary periods. The RV observations were accompanied by contemporaneous photometric observations. We derive stellar rotation periods of 122.1 ± 2.2 d and 96.7 ± 3.7 d for GJ 251 and HD 238090, respectively. The RV data of all three stars exhibit significant signals at the rotational period or its first harmonic. For GJ 251 and Lalande 21185, we also find long-period signals around 600 d, and 2900 d, respectively, which we tentatively attribute to long-term magnetic cycles. We apply a Bayesian approach to carefully model the Keplerian signals simultaneously with the stellar activity using Gaussian process regression models and extensively search for additional significant planetary signals hidden behind the stellar activity. Current planet formation theories suggest that the three systems represent a common architecture, consistent with formation following the core accretion paradigm.
Acceso Abierto
The CARMENES search for exoplanets around M dwarfs. The He I infrared triplet lines in PHOENIX models of M 2-3 V stars
(EDP Sciences, 2020-06-24) Hintz, D.; Fuhrmeister, B.; Czesla, S.; Schmitt, H. M. M.; Schweitzer, A.; Nagel, E.; Johnson, E. N.; Caballero, J. A.; Zechmeister, M.; Jeffers, S. V.; Reiners, A.; Ribas, I.; Amado, P. J.; Quirrenbach, A.; Anglada Escudé, G.; Bauer, F. F.; Béjar, V. J. S.; Cortés Contreras, M.; Dreizler, S.; Galadí Enríquez, D.; Guenther, E. W.; Hauschildt, P. H.; Kaminski, A.; Kürster, M.; Lafarga, M.; López del Fresno, M.; Montes, D.; Morales, J. C.; Deutsches Zentrum für Luft- und Raumfahrt (DLR); Deutsche Forschungsgemeinschaft (DFG); Agencia Estatal de Investigación (AEI); Ministerio de Economía y Competitividad (MINECO); 0000-0002-5274-2589; 0000-0001-6470-2907; 0000-0002-6532-4378; 0000-0003-1212-5225; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
The He » I infrared (IR) line at a vacuum wavelength of 10 833 Å is a diagnostic for the investigation of atmospheres of stars and planets orbiting them. For the first time, we study the behavior of the He » I IR line in a set of chromospheric models for M-dwarf stars, whose much denser chromospheres may favor collisions for the level population over photoionization and recombination, which are believed to be dominant in solar-type stars. For this purpose, we use published PHOENIX models for stars of spectral types M2 V and M3 V and also compute new series of models with different levels of activity following an ansatz developed for the case of the Sun. We perform a detailed analysis of the behavior of the He I IR line within these models. We evaluate the line in relation to other chromospheric lines and also the influence of the extreme ultraviolet (EUV) radiation field. The analysis of the He » I IR line strengths as a function of the respective EUV radiation field strengths suggests that the mechanism of photoionization and recombination is necessary to form the line for inactive models, while collisions start to play a role in our most active models. Moreover, the published model set, which is optimized in the ranges of the Na » I D2, Hα, and the bluest Ca » II IR triplet line, gives an adequate prediction of the He » I IR line for most stars of the stellar sample. Because especially the most inactive stars with weak He » I IR lines are fit worst by our models, it seems that our assumption of a 100% filling factor of a single inactive component no longer holds for these stars. © ESO 2020.
Acceso Abierto
The CARMENES search for exoplanets around M dwarfs: LP 714-47 b (TOI 442.01): populating the Neptune desert
(EDP Sciences, 2020-12-11) Dreizler, S.; Crossfield, J. M.; Kossakowski, D.; Plavchan, P.; Jeffers, S. V.; Kemmer, J.; Luque, R.; Espinoza, N.; Pallé, E.; Stassun, K.; Matthews, E.; Gorjian, V.; Kawauchi, K.; Kielkopf, J. F.; Hidalgo, D.; Kosiarek, M. R.; Kreidberg, L.; Huber, D.; Livingston, J.; Jehin, E.; Jensen, E. L. N.; Mann, A.; Madrigal Aguado, A.; Kane, S. R.; Mocnik, T.; Morales, J. C.; Klahr, H.; Murgas Alcaino, F.; Kürster, M.; Lafarga, M.; Nowak, G.; Louie, D.; Parviainen, H.; Passegger, V. M.; Matson, R. A.; Pozuelos, F. J.; Quirrenbach, A.; Muirhead, P. S.; Robertson, P.; Nandakumar, S.; Narita, N.; Rose, M. E.; Roy, A.; Oshagh, M.; Schlieder, J.; Shectman, S.; Pollacco, D.; Senavci, H. V.; Reefe, M.; Ribas, I.; Villaseñor, J. N.; Rodríguez López, C.; Weiss, L. M.; Wittrock, J.; Schweitzer, A.; Zohrabi, F.; Cale, B.; Tanner, A.; Lillo Box, J.; Teske, J.; Twicken, J. D.; Lalitha, S.; Reiners, A.; Wang, S. X.; Bitsch, B.; Zapatero Osorio, M. R.; Yilmaz, M.; Ricker, G.; Caballero, J. A.; Schlecker, M.; Seager, S.; Zechmeister, M.; Jenkins, J. M.; Aceituno, J.; Soubkiou, A.; Barkaoui, K.; Chaturvedi, P.; Hatzes, A. P.; Bauer, F. F.; Vanderspek, R.; Latham, D. W.; Benkhaldoun, Z.; Beichman, C.; Winn, J. N.; Butler, R. P.; Caldwell, D. A.; Amado, P. J.; Christianesen, J. L.; Barbieri, M.; Batalha, N. M.; Collins, K. A.; Benneke, B.; Combs, D.; Cortés Contreras, M.; Burt, J.; Daylan, T.; Chintada, A.; Chontos, A.; Evans, P.; Ciardi, D. R.; Cifuentes, C.; Flowers, E. E.; Fukui, A.; Collins, K. I.; Furlan, E.; Gaidos, E.; Crane, J. D.; Gillon, M.; Dragomir, D.; Esparza Borges, E.; Hellier, C.; Feng, F.; Howard, A. W.; Howell, Steve B.; Fulton, B.; Isaacson, I.; Geneser, C.; Giacalone, S.; Kaminski, A.; Gonzales, E.; Junta de Andalucia; National Aeronautics and Space Administration (NASA); European Research Council (ERC); Agencia Estatal de Investigación (AEI); Ministerio de Economía y Competitividad (MINECO); Generalitat de Catalunya; Science and Technology Facilities Council (STFC); Centre National de la Recherche Scientifique (CNRS); Japan Society for the Promotion of Science (KAKENHI); 0000-0001-6187-5941; 0000-0002-8864-1667; 0000-0003-3929-1442; 0000-0003-0987-1593; 0000-0002-7349-1387; 0000-0003-3742-1987; 0000-0002-8388-6040; 0000-0003-1715-5087; Centros de Excelencia Severo Ochoa, INSTITUTO DE ASTROFISICA DE ANDALUCIA (IAA), SEV-2017-0709; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
We report the discovery of a Neptune-like planet (LP 714-47 b, P = 4.05204 d, m(b) = 30.8 +/- 1.5M(circle plus), R-b = 4.7 +/- 0.3 R-circle plus) located in the "hot Neptune desert". Confirmation of the TESS Object of Interest (TOI 442.01) was achieved with radial-velocity follow-up using CARMENES, ESPRESSO, HIRES, iSHELL, and PFS, as well as from photometric data using TESS, Spitzer, and ground-based photometry from MuSCAT2, TRAPPIST-South, MONET-South, the George Mason University telescope, the Las Cumbres Observatory Global Telescope network, the El Sauce telescope, the TuBTAK National Observatory, the University of Louisville Manner Telescope, and WASP-South. We also present high-spatial resolution adaptive optics imaging with the Gemini Near-Infrared Imager. The low uncertainties in the mass and radius determination place LP 714-47 b among physically well-characterised planets, allowing for a meaningful comparison with planet structure models. The host star LP 714-47 is a slowly rotating early M dwarf (T-eff = 3950 +/- 51 K) with a mass of 0.59 +/- 0.02M(circle dot) and a radius of 0.58 +/- 0.02R(circle dot). From long-term photometric monitoring and spectroscopic activity indicators, we determine a stellar rotation period of about 33 d. The stellar activity is also manifested as correlated noise in the radial-velocity data. In the power spectrum of the radial-velocity data, we detect a second signal with a period of 16 days in addition to the four-day signal of the planet. This could be shown to be a harmonic of the stellar rotation period or the signal of a second planet. It may be possible to tell the difference once more TESS data and radial-velocity data are obtained.
Acceso Abierto
The CARMENES search for exoplanets around M dwarfs: Measuring precise radial velocities in the near infrared: The example of the super-Earth CD Cet b
(EDP Sciences, 2020-08-10) Bauer, F. F.; Zechmeister, M.; Kaminski, A.; Rodríguez López, C.; Caballero, J. A.; Azzaro, M.; Stahl, S.; Kossakowski, D.; Quirrenbach, A.; Becerril Jarque, S.; Rodríguez, E.; Amado, P. J.; Seifert, W.; Reiners, A.; Schäfer, S.; Ribas, I.; Béjar, V. J. S.; Cortés Contreras, M.; Dreizler, S.; Hatzes, A.; Henning, T.; Jeffers, S. V.; Kürster, M.; Lafarga, M.; Montes, D.; Morales, J. C.; Schmitt, H. M. M.; Schweitzer, A.; Solano, Enrique; European Research Council (ERC); Agencia Estatal de Investigación (AEI); Ministerio de Economía y Competitividad (MINECO); Deutsche Forschungsgemeinschaft (DFG); 0000-0003-1212-5225; 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; Centros de Excelencia Severo Ochoa, INSTITUTO DE ASTROFÍSICA DE CANARIAS (IAC), SEV-2015-0548
The high-resolution, dual channel, visible and near-infrared spectrograph CARMENES offers exciting opportunities for stellar and exoplanetary research on M dwarfs. In this work we address the challenge of reaching the highest radial velocity precision possible with a complex, actively cooled, cryogenic instrument, such as the near-infrared channel. We describe the performance of the instrument and the work flow used to derive precise Doppler measurements from the spectra. The capability of both CARMENES channels to detect small exoplanets is demonstrated with the example of the nearby M5.0 V star CD Cet (GJ 1057), around which we announce a super-Earth (4.0 ± 0.4 M· ) companion on a 2.29 d orbit. © 2020 ESO.
Acceso Abierto
The CARMENES search for exoplanets around M dwarfs: Rubidium abundances in nearby cool stars
(EDP Sciences, 2020-10-23) Abia, C.; Tabernero, H. M.; Korotin, S. A.; Montes, D.; Marfil, E.; Caballero, J. A.; Straniero, O.; Prantzos, N.; Ribas, I.; Reiners, A.; Quirrenbach, A.; Amado, P. J.; Béjar, V. J. S.; Cortés Contreras, M.; Dreizler, S.; Henning, T.; Jeffers, S. V.; Kaminski, A.; Kürster, M.; Lafarga, M.; López Gallifa, A.; Morales, J. C.; Nagel, E.; Passegger, V. M.; Pedraz, S.; Rodríguez López, C.; Schweitzer, A.; Zechmeister, M.; Fundacao para a Ciencia e a Tecnologia (FCT); Generalitat de Catalunya; National Aeronautics and Space Administration (NASA); Agencia Estatal de Investigación (AEI); López Gallifa, A. [0000-0001-6049-9366]; Tabernero, H. [0000-0002-8087-4298]; Montes, D. [0000-0002-7779-238X]; Korotin, S. [0000-0002-4058-8780]; 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; Centros de Excelencia Severo Ochoa, INSTITUTO DE ASTROFÍSICA DE CANARIAS (IAC), SEV-2015-0548; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Due to their ubiquity and very long main-sequence lifetimes, abundance determinations in M dwarfs provide a powerful and alternative tool to GK dwarfs to study the formation and chemical enrichment history of our Galaxy. In this study, abundances of the neutron-capture elements Rb, Sr, and Zr are derived, for the first time, in a sample of nearby M dwarfs. We focus on stars in the metallicity range − 0.5 ≲ [Fe/H] ≲ +0.3, an interval poorly explored for Rb abundances in previous analyses. To do this we use high-resolution, high-signal-to-noise-ratio, optical and near-infrared spectra of 57 M dwarfs observed with CARMENES. The resulting [Sr/Fe] and [Zr/Fe] ratios for most M dwarfs are almost constant at about the solar value, and are identical to those found in GK dwarfs of the same metallicity. However, for Rb we find systematic underabundances ([Rb/Fe] < 0.0) by a factor two on average. Furthermore, a tendency is found for Rb – but not for other heavy elements (Sr, Zr) – to increase with increasing metallicity such that [Rb/Fe] ≳ 0.0 is attained at metallicities higher than solar. These are surprising results, never seen for any other heavy element, and are difficult to understand within the formulation of the s- and r-processes, both contributing sources to the Galactic Rb abundance. We discuss the reliability of these findings for Rb in terms of non-LTE (local thermodynamic equilibrium) effects, stellar activity, or an anomalous Rb abundance in the Solar System, but no explanation is found. We then interpret the full observed [Rb/Fe] versus [Fe/H] trend within the framework of theoretical predictions from state-of-the-art chemical evolution models for heavy elements, but a simple interpretation is not found either. In particular, the possible secondary behaviour of the [Rb/Fe] ratio at super-solar metallicities would require a much larger production of Rb than currently predicted in AGB stars through the s-process without overproducing Sr and Zr.