Examinando por Autor "Amado, P. J."

Mostrando 1 - 11 de 11

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 super-Earth on a close-in orbit around the M1V star GJ 740 A HADES and CARMENES collaboration
(EDP Sciences, 2021-04-07) Toledo Padrón, B.; Suárez Mascareño, A.; Rebolo, R.; Pinamonti, M.; Perger, M.; Scandariato, G.; Damasso, M.; Sozzetti, A.; Moldonado, J.; Desidera, S.; Ribas, I.; Micela, G.; Affer, L.; González Álvarez, E.; Leto, G.; Pagano, I.; Zanmar Sánchez, R.; Giacobbe, P.; Herrero, E.; Morales, J. C.; Amado, P. J.; Caballero, J. A.; Quirrenbach, A.; Reiners, A.; Zechmeister, M.; González Hernández, Carmen; Agencia Estatal de Investigación (AEI); Ministerio de Economía y Competitividad (MINECO); Generalitat de Catalunya
Context. M-dwarfs have proven to be ideal targets for planetary radial velocity (RV) searches due to their higher planet-star mass contrast, which favors the detection of low-mass planets. The abundance of super-Earth and Earth-like planets detected around this type of star motivates further such research on hosts without reported planetary companions. Aims. The HADES and CARMENES programs are aimed at carrying out extensive searches of exoplanetary systems around M-type stars in the northern hemisphere, allowing us to address, in a statistical sense, the properties of the planets orbiting these objects. In this work, we perform a spectroscopic and photometric study of one of the program stars (GJ 740), which exhibits a short-period RV signal that is compatible with a planetary companion. Methods. We carried out a spectroscopic analysis based on 129 HARPS-N spectra taken over a time span of 6 yr combined with 57 HARPS spectra taken over 4 yr, as well as 32 CARMENES spectra taken during more than 1 yr, resulting in a dataset with a time coverage of 10 yr. We also relied on 459 measurements from the public ASAS survey with a time-coverage of 8 yr, along with 5 yr of photometric magnitudes from the EXORAP project taken in the V, B, R, and I filters to carry out a photometric study. Both analyses were made using Markov chain Monte Carlo simulations and Gaussian process regression to model the activity of the star. Results. We present the discovery of a short-period super-Earth with an orbital period of 2.37756−0.00011+0.00013 d and a minimum mass of 2.96−0.48+0.50 M⊕. We offer an update to the previously reported characterization of the magnetic cycle and rotation period of the star, obtaining values of Prot = 35.563 ± 0.071 d and Pcycle = 2800 ± 150 d. Furthermore, the RV time series exhibits a possibly periodic long-term signal, which might be related to a Saturn-mass planet of ~100 M⊕.
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
Gliese 49: activity evolution and detection of a super-Earth A HADES and CARMENES collaboration
(EDP Sciences, 2019-04-24) Perger, M.; Scandariato, G.; Ribas, I.; Morales, J. C.; Affer, L.; Azzaro, M.; Amado, P. J.; Anglada Escudé, G.; Baroch, D.; Barrado, D.; Bauer, F. F.; Béjar, V. J. S.; Caballero, J. A.; Cortés Contreras, M.; Damasso, M.; Dreizler, S.; González Cuesta, L.; Guenther, E. W.; Henning, T.; Herrero, E.; Jeffers, S. V.; Kaminski, A.; Kürster, M.; Lafarga, M.; Leto, G.; López González, M. J.; Maldonado, J.; Micela, G.; Montes, D.; Pinamonti, M.; Quirrenbach, A.; Rebolo, R.; Reiners, A.; Rodríguez, E.; Rodríguez López, C.; Schimitt, J. H. M. M.; Sozzetti, A.; Suárez Mascareño, A.; Toledo Padrón, B.; Zanmar Sánchez, R.; Zapatero Osorio, M. R.; Zechmeister, M.; González Hernández, Carmen; Ministerio de Economía y Competitividad (MINECO); European Commission (EC); Agencia Estatal de Investigación (AEI); 0000-0001-7098-0372; 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. Small planets around low-mass stars often show orbital periods in a range that corresponds to the temperate zones of their host stars which are therefore of prime interest for planet searches. Surface phenomena such as spots and faculae create periodic signals in radial velocities and in observational activity tracers in the same range, so they can mimic or hide true planetary signals. Aims. We aim to detect Doppler signals corresponding to planetary companions, determine their most probable orbital configurations, and understand the stellar activity and its impact on different datasets. Methods. We analyzed 22 yr of data of the M1.5 V-type star Gl 49 (BD+61 195) including HARPS-N and CARMENES spectrographs, complemented by APT2 and SNO photometry. Activity indices are calculated from the observed spectra, and all datasets are analyzed with periodograms and noise models. We investigated how the variation of stellar activity imprints on our datasets. We further tested the origin of the signals and investigate phase shifts between the different sets. To search for the best-fit model we maximize the likelihood function in a Markov chain Monte Carlo approach. Results. As a result of this study, we are able to detect the super-Earth Gl 49b with a minimum mass of 5.6 M⊕. It orbits its host star with a period of 13.85 d at a semi-major axis of 0.090 au and we calculate an equilibrium temperature of 350 K and a transit probability of 2.0%. The contribution from the spot-dominated host star to the different datasets is complex, and includes signals from the stellar rotation at 18.86 d, evolutionary timescales of activity phenomena at 40–80 d, and a long-term variation of at least four years.
Acceso Abierto
Stellar atmospheric parameters of FGK-type stars from high-resolution optical and near-infrared CARMENES spectra
(Oxford Academics: Oxford University Press, 2020-01-10) Marfil, E.; Tabernero, H. M.; Montes, D.; Caballero, J. A.; Soto, M. G.; Kaminski, A.; Nagel, E.; Jeffers, S. V.; Reiners, A.; Ribas, I.; Quirrenbach, A.; Amado, P. J.; González Hernández, Carmen; Fundacao para a Ciencia e a Tecnologia (FCT); Deutsche Forschungsgemeinschaft (DFG); Agencia Estatal de Investigación (AEI); Ministerio de Economía y Competitividad (MINECO); 0000-0001-8907-4775; 0000-0002-8087-4298; 0000-0002-7349-1387; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
With the purpose of assessing classic spectroscopic methods on high-resolution and high signal-to-noise ratio spectra in the near-infrared wavelength region, we selected a sample of 65 F-, G-, and K-type stars observed with CARMENES, the new, ultra-stable, double channel spectrograph at the 3.5 m Calar Alto telescope. We computed their stellar atmospheric parameters (Teti, log g, 4, and [Fell I]) by means of the STEPAR code, a PYTHON implementation of the equivalent width method that employs the 2017 version of the MOOG code and a grid of MARCS model atmospheres. We compiled four Fe 1 and Fe tl line lists suited to metal-rich dwarfs, metal-poor dwarfs, metal-rich giants, and metal-poor giants that cover the wavelength range from 5300 to 17 100 A, thus substantially increasing the number of identified Fe! and Felt lines up to 653 and 23, respectively, We examined the impact of the near-infrared Fe and Fen lines upon our parameter determinations after an exhaustive literature search, placing special emphasis on the 14 Gala benchmark stars contained in our sample, Even though our parameter determinations remain in good agreement with the literature values, the increase in the number of Fel and Feu lines when the near-infrared region is taken into account reveals a deeper Teff scale that might stem from a higher sensitivity of the near-infrared lines to Tff.C 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society
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 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: Dynamical characterization of the multiple planet system GJ 1148 and prospects of habitable exomoons around GJ 1148 b
(EDP Sciences, 2020-06-03) Trifonov, T.; Lee, M. H.; Kürster, M.; Henning, T.; Grishin, E.; Stock, S.; Tjoa, J.; Caballero, J. A.; Wong, K. H.; Bauer, F. F.; Quirrenbach, A.; Zechmeister, M.; Ribas, I.; Reffert, S.; Reiners, A.; Amado, P. J.; Kossakowski, D.; Azzaro, M.; Béjar, V. J. S.; Cortés Contreras, M.; Dreizler, S.; Hatzes, A. P.; Jeffers, S. V.; Kaminski, A.; Lafarga, M.; Montes, D.; Morales, J. C.; Pavlov, A.; Rodríguez López, C.; Schmitt, H. M. M.; Barnes, R.; Solano, Enrique; Deutsche Forschungsgemeinschaft (DFG); Ministerio de Economía y Competitividad (MINECO); Junta de Andalucía; European Research Council (ERC); Agencia Estatal de Investigación (AEI); Trifonov, T. https://orcid.org/0000-0002-0236-775X; 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. GJ 1148 is an M-dwarf star hosting a planetary system composed of two Saturn-mass planets in eccentric orbits with periods of 41.38 and 532.02 days. Aims. We reanalyze the orbital configuration and dynamics of the GJ 1148 multi-planetary system based on new precise radial velocity measurements taken with CARMENES. Methods. We combined new and archival precise Doppler measurements from CARMENES with those available from HIRES for GJ 1148 and modeled these data with a self-consistent dynamical model. We studied the orbital dynamics of the system using the secular theory and direct N-body integrations. The prospects of potentially habitable moons around GJ 1148 b were examined. Results. The refined dynamical analyses show that the GJ 1148 system is long-term stable in a large phase-space of orbital parameters with an orbital configuration suggesting apsidal alignment, but not in any particular high-order mean-motion resonant commensurability. GJ 1148 b orbits inside the optimistic habitable zone (HZ). We find only a narrow stability region around the planet where exomoons can exist. However, in this stable region exomoons exhibit quick orbital decay due to tidal interaction with the planet. Conclusions. The GJ 1148 planetary system is a very rare M-dwarf planetary system consisting of a pair of gas giants, the inner of which resides in the HZ. We conclude that habitable exomoons around GJ 1148 b are very unlikely to exist. © 2020 T. Trifonov et al.
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 EChO science case
(Springer Link, 2015-11-29) Tinetti, G.; Drossart, P.; Eccleston, P.; Hartogh, P.; Isaak, K.; Linder, M.; Lovis, C.; Micela, G.; Olliver, M.; Puig, L.; Ribas, I.; Schrader, J. R.; Scholz, A.; Watkins, C.; Maillard, J. P.; Abreu, M.; Glasse, A.; Testi, L.; Doel, P.; Magnes, W.; Licandro Goldaracena, J.; Wawer, P.; Zapatero Osorio, M. R.; Decin, L.; Sánz Forcada, J.; Vakili, F.; Aylward, A.; Swain, M.; Sozzetti, A.; Filacchione, G.; Delgado Mena, E.; Read, P.; Lognonné, P.; Irshad, R.; Coates, A.; Cecchi Pestellini, C.; Thrastarson, H.; Brown, L.; Guillot, T.; Strazzulla, G.; Barstow, J. K.; Budaj, J.; Morgante, G.; Pietrzak, R.; Leconte, J.; Hersant, F.; De Sio, A.; Grassi, D.; Selsis, F.; Jarchow, C.; Fouqué, P.; Del Vecchio, C.; Tennyson, J.; Cassan, A.; Fernández Hernández, Maite; Burleigh, M. R.; Cordier, D.; De Witt, J.; Pagano, I.; Ray, T.; Gambicorti, L.; Palla, F.; Maldonado, J.; Biondi, D.; Eiroa, C.; Winek, W.; Ade, P.; Villaver, E.; Temple, J.; Gear, W.; Thompson, S.; Dominic, C.; Galand, M.; Focardi, M.; Cockell, C.; Pace, E.; Dorfi, E.; Bryson, I.; Cavarroc, C.; Pilat Lohinger, E.; Smith, A.; Eymet, V.; MacTavish, C.; Morales, J. C.; Gómez, H.; Stamper, R.; Esposito, M.; Andersen, A.; Azzollini, R.; Maxted, P.; Allende Prieto, C.; Nelson, R.; Gillon, M.; Achilleos, N.; Buchhave, L. A.; Fabrizio, N.; Ciaravella, A.; Claudi, R.; Damasso, M.; Bordé, P.; Figueira, P.; Rickman, H.; Rees, J. M.; Sitek, P.; Fossey, S.; Bakos, G.; Pascale, E.; Laken, B.; Soret, L.; Femenía Castella, B.; Allard, F.; Amado, P. J.; Luzzi, D.; Colomé, J.; Galand, M.; Lammer, H.; Bonford, B.; López Valverde, M. A.; Kerins, E.; Yung, Y.; Espinoza Contreras, M.; Irwin, P.; Herrero, E.; Wright, G.; Guàrdia, J.; Banaszkiewicz, M.; Hoogeeven, R.; Alcala, J.; Guio, P.; Koskinen, T.; Barton, E. J.; Piskunov, N.; Maurin, A. S.; Leto, G.; Boisse, I.; Claret, A.; Massi, F.; Kervella, P.; Börne, P.; Heiter, U.; Hargrave, P.; Fletcher, L.; Sánchez Béjar, V. J.; Bézard, B.; Cabral, A.; Michaut, C.; Winter, B.; Sousa, S.; Giuranna, M.; Batista, V.; Frith, J.; Ballerini, P.; López Morales, M.; Monteiro, M.; Tingley, B. W.; Lanza, N.; Maggio, A.; Lundgaard Rasmussen, I.; Altieri, F.; Covino, E.; Coustenis, A.; Heredero, R. L.; Watson, D.; Coudé du Foresto, V.; Liu, S. J.; Sicardy, B.; Deeg, H. J.; Moses, J.; Rodler, F.; Lithgow Bertelloni, C.; Demangeon, O.; Adybekian, V.; Fletcher, L.; Swinyard, B.; Morales Calderón, M.; Fouqué, P.; Deroo, P.; Lo Cicero, Ugo; Hueso, R.; Iro, N.; González Merino, B.; López Puertas, M.; Capria, M. T.; Danielski, C.; Branduardi Raymont, G.; Luntzer, A.; Gaulme, P.; Bulgarelli, A.; Parmentier, V.; Gerard, J. C.; Alard, C.; Frith, J.; Dobrijévic, M.; Medvedev, A.; Barrado, D.; Jacquemoud, S.; Sethenadh, J.; Readorn, K.; Polichtchouk, I.; Petrov, R.; García Piquer, A.; Tabernero, H. M.; White, G.; Pancrazzi, M.; García López, Ramón; Filacchione, G.; Gómez Leal, I.; Rengel, M.; Gesa, L.; Tanga, P.; Mueller Wodarg, I.; Israelian, G.; Rebolo López, R.; Shore, S.; Peralta, J.; Collura, A.; Giro, E.; Del Val Borro, M.; Griffith, C.; Tecsa, M.; Haigh, J.; Moro Martín, A.; Jones, H.; Gizon, L.; Pezzuto, S.; Giani, E.; Mall, U.; Eales, S.; Graczyk, R.; Ramos Zapata, G.; Krupp, N.; Sánchez Lavega, A.; Fossey, S.; Alonso Floriano, F. J.; Justtanot, K.; Santos, N.; Pérez Hoyos, S.; Savini, G.; Chamberlain, S.; Bowles, N.; Kerschbaum, F.; Tozzi, A.; Turrini, D.; Kipping, D.; Maruquette, J. B.; Correira, A.; Trifoglio, M.; Agúndez, Marcelino; Scandaratio, G.; Snellen, I. A.; Scuderi, S.; Femenía Castella, B.; Prisinzano, L.; Oliva, E.; Hébrard, E.; Lodieu, N.; Forget, F.; Chadney, J.; Showman, A.; Gustin, J.; Vinatier, S.; Charnoz, S.; Affer, L.; Rank Lüftinger, T.; Poretti, E.; Lahav, O.; North, C.; Gerard, J. C.; Murgas Alcaino, F.; Yurchenko, S. N.; Widemann, T.; Ward Thompson, D.; Montañés Rodríguez, P.; Kovács, G.; Valdivieso, M. L.; Moya Bedon, A.; Montalto, M.; Christian Jessen, N.; Venot, O.; Koskinen, T.; Lagage, P. O.; Bellucci, G.; Prinja, R.; Pinfield, D.; Banaszkiewicz, M.; Waldmann, I.; Jones, G.; Morello, G.; Crook, J.; Lim, T.; Parviainen, H.; Pallé, E.; Ramos, A. A.; Sanromá, E.; Waters, R.; Morais, H.; Stiepen, A.; Lellouch, E.; Orton, G.; Rezac, L.; Beaulieu, J. P.; Focardi, M.; Mauskopf, P.; Barlow, M.; Guedel, M.; Waltham, D.; Agnor, C.; Encrenaz, T.; Cerulli, R.; Balado, A.; Bouy, H.; Rebordao, J.; Stolarski, M.; Álvarez Iglesias, C. A.; Adriani, A.; Rocchetto, M.; Norgaard Nielsen, H. U.; Hollis, M.; Selig, A.; Malaguti, G.; Burston, R.; Peña Ramírez, K. Y.; Schmider, F. X.; Baffa, C.; Heyrovsky, D.; Figueira, P.; Piccioni, G.; Ottensamer, R.; Radioti, A.; Yelle, R.; Pantin, E.; Miles Paez, P.; Belmonte Avilés, J. A.; Montes, D.; Varley, R.; Viti, S.; Abe, L.; Pinsard, F.; Tessenyi, M.; Di Giorgio, A.; Turrini, D.; Terenzi, L.; Hubert, B.; Griffin, M.; Barber, R. J.; Cole, R.; Gianotti, F.; Blecka, M.; Wawrzaszk, A.; Middleton, K.; De Kok, R.; Martín Torres, Javier; Kehoe, T.; Cho, J.; Machado, P.; Berry, D.; Wisniowski, T.; Grodent, D.; Rataj, M.; Hornstrup, A.; Kerschbaum, F.; Vandenbussche, B.; Stixrude, L.; González Hernández, Carmen; Rebordao, J. [0000-0002-7418-0345]; Kerschbaum, F. [0000-0001-6320-0980]; Abreu, M. [0000-0002-0716-9568]; Tabernero, H. [0000-0002-8087-4298]; López Puertas, M. [0000-0003-2941-7734]; Jacquemoud, S. [0000-0002-1500-5256]; Tennyson, J. [0000-0002-4994-5238]; Focardi, M. [0000-0002-3806-4283]; Leto, G. [0000-0002-0040-5011]; Lodieu, N. [0000-0002-3612-8968]; Tinetti, G. [0000-0001-6058-6654]; Bulgarelli, A. [0000-0001-6347-0649]; Morales Calderon, M. [0000-0001-9526-9499]; Ward Thompson, D. [0000-0003-1140-2761]; Rebolo, R. [0000-0003-3767-7085]; López Valverde, M. A. [0000-0002-7989-4267]; Gillon, M. [0000-0003-1462-7739]; Morgante, G. [0000-0001-9234-7412]; Pena Ramírez, K. [0000-0002-5855-401X]; Galand, M. [0000-0001-5797-914X]; Pancrazzi, M. [0000-0002-3789-2482]; Pilat Lohinger, E. [0000-0002-5292-1923]; Altieri, F. [0000-0002-6338-8300]; Malaguti, G. [0000-0001-9872-3378]; Sánchez Lavega, A. [0000-0001-7234-7634]; Waldmann, I. [0000-0002-4205-5267]; Kovacs, G. [0000-0002-2365-2330]; Guillot, T. [0000-0002-7188-8428]; Monteiro, M. [0000-0001-5644-0898]; Bellucci, G. [0000-0003-0867-8679]; Baffa, C. [0000-0002-4935-100X]; Olivia, E. [0000-0002-9123-0412]; Tizzi, A. [0000-0002-6725-3825]; Selsis, F. [0000-0001-9619-5356]; Scuderi, Salvatore [0000-0002-8637-2109]; Hersant, F. [0000-0002-2687-7500]; Gear, W. [0000-0001-6789-6196]; Damasso, M. [0000-0001-9984-4278]; Irwin, P. [0000-0002-6772-384X]; Pinfield, D. [0000-0002-7804-4260]; Kipping, D. [0000-0002-4365-7366]; Maldonado, J. [0000-0002-4282-1072]; Pace, E. [0000-0001-5870-1772]; Burleigh, M. [0000-0003-0684-7803]; Chadney, J. [0000-0002-5174-2114]; Moro Martín, A. [0000-0001-9504-8426]; Claret, A. [0000-0002-4045-8134]; Rodríguez, P. [0000-0002-6855-9682]; Bezard, B. [0000-0002-5433-5661]; Gómez, H. [0000-0003-3398-0052]; Maldonado, J. [0000-0002-2218-5689]; Michaut, C. [0000-0002-2578-0117]; Hornstrup, A. [0000-0002-3363-0936]; Scholz, A. [0000-0001-8993-5053]; Sánchez Bejar, V. [0000-0002-5086-4232]; López Heredero, R. [0000-0002-2197-8388]; Sanz Forcada, J. [0000-0002-1600-7835]; Danielski, C. [0000-0002-3729-2663]; Vandenbussche, B. [0000-0002-1368-3109]; Sousa, S. [0000-0001-9047-2965]; Medved, A. [0000-0003-2713-8977]; Tinetti, G. [0000-0001-6058-6654]; Bakos, G. [0000-0001-7204-6727]; Ade, P. [0000-0002-5127-0401]; Amado, P. J. [0000-0002-8388-6040]; Martín Torres, J. [0000-0001-6479-2236]; Correira, A. [0000-0002-8946-8579]; Haigh, J. [0000-0001-5504-4754]; Scandariato, G. [0000-0003-2029-0626]; Guedel, M. [0000-0001-9818-0588]; Piskunov, N. [0000-0001-5742-7767]; Adibekyan, V. [0000-0002-0601-6199]; Pérez Hoyos, S. [0000-0001-9797-4917]; Poretti, E. [0000-0003-1200-0473]; Maggio, A. [0000-0001-5154-6108]; Kervella, P. [0000-0003-0626-1749]; Pascale, E. [0000-0002-3242-8154]; Claudi, R. [0000-0001-7707-5105]; Filacchione, G. [0000-0001-9567-0055]; Rickman, H. [0000-0002-9603-6619]; Sanroma, E. [0000-0001-8859-7937]; Agundez, M. [0000-0003-3248-3564]; Montes, D. [0000-0002-7779-238X]; Fletcher, L. [0000-0001-5834-9588]; Rataj, M. [0000-0002-2978-9629]; Stixrude, L. [0000-0003-3778-2432]; Montes, D. [0000-0002-7779-238X]; Morais, M. H. [0000-0001-5333-2736]; Hueso, R. [0000-0003-0169-123X]; Yurchenko, S. [0000-0001-9286-9501]; Morales, J. C. [0000-0003-0061-518X]; Pérez Hoyos, S. [0000-0002-2587-4682]; Santos, N. [0000-0003-4422-2919]; Peralta, J. [0000-0002-6823-1695]; Budaj, J. [0000-0002-9125-7340]; Barlow, M. [0000-0002-3875-1171]; Deeg, H. [0000-0003-0047-4241]; Grassi, D. [0000-0003-1653-3066]; Piccioni, G. [0000-0002-7893-6808]; Barton, E. [0000-0001-5945-9244]; Abreu, M. [0000-0002-0716-9568]; Ribas, I. [0000-0002-6689-0312]; Coates, A. [0000-0002-6185-3125]; García Ramón, J. [0000-0002-8204-6832]; Bouy, H. [0000-0002-7084-487X[; Lognonne, P. [0000-0002-1014-920X]; Demangeon, O. [0000-0001-7918-0355]; Ray, T. [0000-0002-2110-1068]; Guio, P. [0000-0002-1607-5862]; Tanga, P. [0000-0002-2718-997X]; Delgado, M. E. [0000-0003-4434-2195]; Leto, G. [0000-0002-0040-5011]; Prisinzano, L. [0000-0002-8893-2210]; Barstow, J. [0000-0003-3726-5419]; Balado, A. [0000-0003-4268-2516]; Lithgow Bertelloni, C. [0000-0003-0924-6587]; Zapatero Osorio, M. R. [0000-0001-5664-2852]; Affer, L. [0000-0001-5600-3778]; Ciaravella, A. [0000-0002-3127-8078]; Barrado Navascues, D. [0000-0002-5971-9242]; Figueira, P. [0000-0001-8504-283X]; Covino, E. [0000-0002-6187-6685]; Venot, O. [0000-0003-2854-765X]; Cabral, A. [0000-0002-9433-871X]; Watson, D. [0000-0002-4465-8264]; Turrini, D. [0000-0002-1923-7740]
The discovery of almost two thousand exoplanets has revealed an unexpectedly diverse planet population. We see gas giants in few-day orbits, whole multi-planet systems within the orbit of Mercury, and new populations of planets with masses between that of the Earth and Neptune—all unknown in the Solar System. Observations to date have shown that our Solar System is certainly not representative of the general population of planets in our Milky Way. The key science questions that urgently need addressing are therefore: What are exoplanets made of? Why are planets as they are? How do planetary systems work and what causes the exceptional diversity observed as compared to the Solar System? The EChO (Exoplanet Characterisation Observatory) space mission was conceived to take up the challenge to explain this diversity in terms of formation, evolution, internal structure and planet and atmospheric composition. This requires in-depth spectroscopic knowledge of the atmospheres of a large and well-defined planet sample for which precise physical, chemical and dynamical information can be obtained. In order to fulfil this ambitious scientific program, EChO was designed as a dedicated survey mission for transit and eclipse spectroscopy capable of observing a large, diverse and well-defined planet sample within its 4-year mission lifetime. The transit and eclipse spectroscopy method, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allows us to measure atmospheric signals from the planet at levels of at least 10−4 relative to the star. This can only be achieved in conjunction with a carefully designed stable payload and satellite platform. It is also necessary to provide broad instantaneous wavelength coverage to detect as many molecular species as possible, to probe the thermal structure of the planetary atmospheres and to correct for the contaminating effects of the stellar photosphere. This requires wavelength coverage of at least 0.55 to 11 μm with a goal of covering from 0.4 to 16 μm. Only modest spectral resolving power is needed, with R ~ 300 for wavelengths less than 5 μm and R ~ 30 for wavelengths greater than this. The transit spectroscopy technique means that no spatial resolution is required. A telescope collecting area of about 1 m2 is sufficiently large to achieve the necessary spectro-photometric precision: for the Phase A study a 1.13 m2 telescope, diffraction limited at 3 μm has been adopted. Placing the satellite at L2 provides a cold and stable thermal environment as well as a large field of regard to allow efficient time-critical observation of targets randomly distributed over the sky. EChO has been conceived to achieve a single goal: exoplanet spectroscopy. The spectral coverage and signal-to-noise to be achieved by EChO, thanks to its high stability and dedicated design, would be a game changer by allowing atmospheric composition to be measured with unparalleled exactness: at least a factor 10 more precise and a factor 10 to 1000 more accurate than current observations. This would enable the detection of molecular abundances three orders of magnitude lower than currently possible and a fourfold increase from the handful of molecules detected to date. Combining these data with estimates of planetary bulk compositions from accurate measurements of their radii and masses would allow degeneracies associated with planetary interior modelling to be broken, giving unique insight into the interior structure and elemental abundances of these alien worlds. EChO would allow scientists to study exoplanets both as a population and as individuals. The mission can target super-Earths, Neptune-like, and Jupiter-like planets, in the very hot to temperate zones (planet temperatures of 300–3000 K) of F to M-type host stars. The EChO core science would be delivered by a three-tier survey. The EChO Chemical Census: This is a broad survey of a few-hundred exoplanets, which allows us to explore the spectroscopic and chemical diversity of the exoplanet population as a whole. The EChO Origin: This is a deep survey of a subsample of tens of exoplanets for which significantly higher signal to noise and spectral resolution spectra can be obtained to explain the origin of the exoplanet diversity (such as formation mechanisms, chemical processes, atmospheric escape). The EChO Rosetta Stones: This is an ultra-high accuracy survey targeting a subsample of select exoplanets. These will be the bright “benchmark” cases for which a large number of measurements would be taken to explore temporal variations, and to obtain two and three dimensional spatial information on the atmospheric conditions through eclipse-mapping techniques. If EChO were launched today, the exoplanets currently observed are sufficient to provide a large and diverse sample. The Chemical Census survey would consist of > 160 exoplanets with a range of planetary sizes, temperatures, orbital parameters and stellar host properties. Additionally, over the next 10 years, several new ground- and space-based transit photometric surveys and missions will come on-line (e.g. NGTS, CHEOPS, TESS, PLATO), which will specifically focus on finding bright, nearby systems. The current rapid rate of discovery would allow the target list to be further optimised in the years prior to EChO’s launch and enable the atmospheric characterisation of hundreds of planets.
Acceso Abierto
Two temperate earth-mass planets orbiting the nearby star GJ 1002
(EDP Sciences, 2023-01-27) Suárez Mascareño, A.; González Álvarez, E.; Zapatero Osorio, M. R.; Lillo Box, J.; Faria, J. P.; Passegger, V. M.; Figueira, P.; Sozzetti, A.; Rebolo López, R.; Pepe, F.; Santos, N. C.; Cristiani, S.; Lovis, C.; Silva, André; Ribas, I.; Amado, P. J.; Caballero, J. A.; Quirrenbach, A.; Reiners, A.; Zechmeister, M.; Adibekyan, V.; Alibert, Y.; Béjar, V. J. S.; Benatti, S.; D´Odorico, V.; Damasso, M.; Delisle, J. B.; Di Marcantonio, P.; Dreizler, S.; Ehrenreich, D.; Hatzes, A. P.; Hara, N. C.; Henning, T.; Kaminski, A.; López González, M. J.; Martins, C. J. A. P.; Micela, G.; Montes, D.; Pallé, E.; Pedraz, S.; Rodríguez Martínez, Eloy; Rodríguez López, C.; Tal Or, L.; Sousa, S. G.; Udry, S.; González Hernández, Carmen; European Commission (EC); Ministerio de Ciencia e Innovación (MICINN); Agencia Estatal de Investigación (AEI); Consejo Superior de Investigaciones Científicas (CSIC); Fundacao para a Ciencia e a Tecnologia (FCT); Junta de Andalucía; Swiss National Science Foundation (SNSF); Cabildo de Gran Canaria
We report the discovery and characterisation of two Earth-mass planets orbiting in the habitable zone of the nearby M-dwarf GJ 1002 based on the analysis of the radial-velocity (RV) time series from the ESPRESSO and CARMENES spectrographs. The host star is the quiet M5.5 V star GJ 1002 (relatively faint in the optical, V ~ 13.8 mag, but brighter in the infrared, J ~ 8.3 mag), located at 4.84 pc from the Sun. We analyse 139 spectroscopic observations taken between 2017 and 2021. We performed a joint analysis of the time series of the RV and full-width half maximum (FWHM) of the cross-correlation function (CCF) to model the planetary and stellar signals present in the data, applying Gaussian process regression to deal with the stellar activity. We detect the signal of two planets orbiting GJ 1002. GJ 1002 b is a planet with a minimum mass mp sin i of 1.08 ± 0.13 M⊕ with an orbital period of 10.3465 ± 0.0027 days at a distance of 0.0457 ± 0.0013 au from its parent star, receiving an estimated stellar flux of 0.67 F⊕. GJ 1002 c is a planet with a minimum mass mp sin i of 1.36 ± 0.17 M⊕ with an orbital period of 20.202 ± 0.013 days at a distance of 0.0738 ± 0.0021 au from its parent star, receiving an estimated stellar flux of 0.257 F⊕. We also detect the rotation signature of the star, with a period of 126 ± 15 days. We find that there is a correlation between the temperature of certain optical elements in the spectrographs and changes in the instrumental profile that can affect the scientific data, showing a seasonal behaviour that creates spurious signals at periods longer than ~200 days. GJ 1002 is one of the few known nearby systems with planets that could potentially host habitable environments. The closeness of the host star to the Sun makes the angular sizes of the orbits of both planets (~9.7 mas and ~15.7 mas, respectively) large enough for their atmosphere to be studied via high-contrast high-resolution spectroscopy with instruments such as the future spectrograph ANDES for the ELT or the LIFE mission.