Examinando por Autor "Cifuentes, C."

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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 catalog of M dwarfs VI. A time-resolved Ca II H&K catalog from archival data
(EDP Sciences, 2021-08-20) Perdelwitz, V.; Mittag, M.; Tal Or, L.; Schmitt, J. H. M. M.; Caballero, J. A.; Jeffers, S. V.; Reiners, A.; Schweitzer, A.; Trifonov, T.; Ribas, I.; Quirrenbach, A.; Amado, P. J.; Seifert, W.; Cifuentes, C.; Cortés Contreras, M.; Montes, D.; Revilla, D.; Skrzypinski, S. L.; Agencia Estatal de Investigación (AEI); Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC; Centro de Excelencia Científica Severo Ochoa Instituto de Astrofísica de Canarias; Perdelwitz, V. [0000-0002-6859-0882]; Tal Or, L. [0000-0003-3757-1440]; Caballero, J. A. [0000-0002-7349-1387]; Reiners, A. [0000-0003-1242-5922]; Schweitzer, A. [0000-0002-1624-0389]; Ribas, I. [0000-0002-6689-0312]; Amado, P. J. [0000-0001-8012-3788]; Cifuentes, C. [0000-0003-1715-5087]; Cortés Contreras, M. [0000-0003-3734-9866]; Skrzypinski, S. L. [0000-0002-0926-9888]; 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
Context. Radial-velocity (RV) jitter caused by stellar magnetic activity is an important factor in state-of-the-art exoplanet discovery surveys such as CARMENES. Stellar rotation, along with heterogeneities in the photosphere and chromosphere caused by activity, can result in false-positive planet detections. Hence, it is necessary to determine the stellar rotation period and compare it to any putative planetary RV signature. Long-term measurements of activity indicators such as the chromospheric emission in the Ca II H&K lines (RHK′) enable the identification of magnetic activity cycles. Aims. In order to determine stellar rotation periods and study the long-term behavior of magnetic activity of the CARMENES guaranteed time observations (GTO) sample, it is advantageous to extract RHK′ time series from archival data, since the CARMENES spectrograph does not cover the blue range of the stellar spectrum containing the Ca II H&K lines. Methods. We have assembled a catalog of 11 634 archival spectra of 186 M dwarfs acquired by seven different instruments covering the Ca II H&K regime: ESPaDOnS, FEROS, HARPS, HIRES, NARVAL, TIGRE, and UVES. The relative chromospheric flux in these lines, RHK′, was directly extracted from the spectra by rectification with PHOENIX synthetic spectra via narrow passbands around the Ca II H&K line cores. Results. The combination of archival spectra from various instruments results in time series for 186 stars from the CARMENES GTO sample. As an example of the use of the catalog, we report the tentative discovery of three previously unknown activity cycles of M dwarfs. Conclusions. We conclude that the method of extracting with the use of model spectra yields consistent results for different instruments and that the compilation of this catalog will enable the analysis of long-term activity time series for a large number of M dwarfs.
Acceso Abierto
Exomoons in the Habitable Zones of M Dwarfs
(The Institute of Physics (IOP), 2019-12-26) Martínez Rodríguez, H.; Caballero, J. A.; Cifuentes, C.; Piro, A.; Barnes, R.; National Aeronautics and Space Administration (NASA); Agencia Estatal de Investigación (AEI); Martínez Rodríguez, H. [0000-0002-1919-228X]; Caballero, J. A. [0000-0002-7349-1387]; Cifuentes, C. [0000-0003-1715-5087]; Piro, A. L. [0000-0001-6806-0673]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
M dwarfs host most of the exoplanets in the local Milky Way. Some of these planets, ranging from sub-Earths to super-Jupiters, orbit in their stars' habitable zones (HZs), although many likely possess surface environments that preclude habitability. Moreover, exomoons around these planets could harbor life for long timescales and thus may also be targets for biosignature surveys. Here we investigate the potential habitability, stability, and detectability of exomoons around exoplanets orbiting M dwarfs. We first compile an updated list of known M-dwarf exoplanet hosts, comprising 109 stars and 205 planets. For each M dwarf, we compute and update precise luminosities with the Virtual Observatory spectral energy distribution Analyzer and Gaia DR2 parallaxes to determine inner and outer boundaries of their HZs. For each planet, we retrieve (or, when necessary, homogeneously estimate) their masses and radii, calculate the long-term dynamical stability of hypothetical moons, and identify those planets that can support habitable moons. We find that 33 exoplanet candidates are located in the HZs of their host stars and that four of them could host Moon- to Titan-mass exomoons for timescales longer than the Hubble time.
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: 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.