Examinando por Autor "Zapatero Osorio, M. R."

Mostrando 1 - 12 de 12

Acceso Abierto
A sub-Neptune and a non-transiting Neptune-mass companion unveiled by ESPRESSO around the bright late-F dwarf HD 5278 (TOI-130)
(EDP Sciences, 2021-04-14) Sozzetti, A.; Damasso, M.; Bonomo, A. S.; Alibert, Y.; Sousa, S. G.; Adibekyan, V.; Zapatero Osorio, M. R.; González Hernández, J. I.; Barros, S. C. C.; Lillo Box, J.; Stassun, K. G.; Winn, J. N.; Cristiani, S.; Pepe, Francesco; Rebolo, R.; Santos, Nuno C.; Allart, R.; Barclay, T.; Bouchy, F.; Cabral, A.; Ciardi, D. R.; Di Marcantonio, P.; D´Odorico, V.; Ehrenreich, D.; Fausnaugh, M.; Figueira, P.; Haldemann, J.; Jenkins, J. M.; Latham, D. W.; Lavie, B.; Lo Curto, G.; Lovis, C.; Martins, C. J. A. P.; Mégevand, D.; Mehner, A.; Micela, G.; Molaro, P.; Nunes, Nelson J.; Oshagh, M.; Otegi, Jon F.; Pallé, E.; Poretti, E.; Ricker, George; Rodríguez, D.; Seager, S.; Suárez Mascareño, A.; Twicken, J. D.; Udry, S.; Istituto Nazionale di Astrofisica (INAF); Agenzia Spaziale Italiana (ASI); iss National Science Foundation (SNSF); Fundacao para a Ciencia e a Tecnologia (FCT); European Commission (EC); European Research Council (ERC); Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI) http://dx.doi.org/10.13039/501100011033; Sozzetti, A. [0000-0002-7504-365X]; Nunes, N. [0000-0002-3837-6914]; Haldemann, J. [0000-0003-1231-2389]
Context. Transiting sub-Neptune-type planets, with radii approximately between 2 and 4 R⊕, are of particular interest as their study allows us to gain insight into the formation and evolution of a class of planets that are not found in our Solar System. Aims. We exploit the extreme radial velocity (RV) precision of the ultra-stable echelle spectrograph ESPRESSO on the VLT to unveil the physical properties of the transiting sub-Neptune TOI-130 b, uncovered by the TESS mission orbiting the nearby, bright, late F-type star HD 5278 (TOI-130) with a period of Pb = 14.3 days. Methods. We used 43 ESPRESSO high-resolution spectra and broad-band photometry information to derive accurate stellar atmospheric and physical parameters of HD 5278. We exploited the TESS light curve and spectroscopic diagnostics to gauge the impact of stellar activity on the ESPRESSO RVs. We performed separate as well as joint analyses of the TESS photometry and the ESPRESSO RVs using fully Bayesian frameworks to determine the system parameters. Results. Based on the ESPRESSO spectra, the updated stellar parameters of HD 5278 are Teff = 6203 ± 64 K, log g = 4.50 ± 0.11 dex, [Fe/H] = −0.12 ± 0.04 dex, M⋆ = 1.126−0.035+0.036 M⊙, and R⋆ = 1.194−0.016+0.017 R⊙. We determine HD 5278 b’s mass and radius to be Mb = 7.8−1.4+1.5 M⊕ and Rb = 2.45 ± 0.05R⊕. The derived mean density, ϱb = 2.9−0.5+0.6 g cm−3, is consistent with the bulk composition of a sub-Neptune with a substantial (~ 30%) water mass fraction and with a gas envelope comprising ~17% of the measured radius. Given the host brightness and irradiation levels, HD 5278 b is one of the best targetsorbiting G-F primaries for follow-up atmospheric characterization measurements with HST and JWST. We discover a second, non-transiting companion in the system, with a period of Pc = 40.87−0.17+0.18 days and a minimum mass of Mc sin ic = 18.4−1.9+1.8 M⊕. We study emerging trends in parameters space (e.g., mass, radius, stellar insolation, and mean density) of the growing population of transiting sub-Neptunes, and provide statistical evidence for a low occurrence of close-in, 10 − 15M⊕ companions around G-F primaries with Teff ≳ 5500 K.
Acceso Abierto
Discriminating between hazy and clear hot-Jupiter atmospheres with CARMENES.
(EDP Sciences, 2020-10-27) Sánchez López, A.; López Puertas, M.; Snellen, Ignas; Nagel, E.; Bauer, F. F.; Pallé, E.; Tal Or, L.; Amado, P. J.; Caballero, P. J.; Czesla, S.; Nortmann, L.; Reiners, A.; Ribas, I.; Quirrenbach, A.; Aceituno, J.; Béjar, V. J. S.; Casasayas Barris, N.; Henning, T.; Molaverdikhani, K.; Montes, D.; Stangret, M.; Zapatero Osorio, M. R.; Zechmeister, M.; European Research Council (ERC); Deutsche Forschungsgemeinschaft (DFG); Agencia Estatal de Investigación (AEI); Ministerio de Economía y Competitividad (MINECO); Ministerio de Ciencia e Innovación (MICINN); Pallé, E. [0000-0003-0987-1593]; Sánchez López, A. [0000-0002-0516-7956]; Nagel, E. [0000-0002-4019-3631]; Montes, D. [0000-0002-7779-238X]; Molaverdikhani, K. [0000-0002-0502-0428]; López Puertas, M. [0000-0003-2941-7734]; Snellen, I. A. G. [0000-0003-1624-3667]; Centro de Excelencia Científica Severo Ochoa Instituto de Astrofísica de Andalucía CSIC, 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. Relatively large radii of some hot Jupiters observed in the ultraviolet and blue-optical are generally interpreted to be due to Rayleigh scattering by high-altitude haze particles. However, the haze composition and its production mechanisms are not fully understood, and observational information is still limited. Aims. We aim to study the presence of hazes in the atmospheres of HD 209458 b and HD 189733 b with high spectral resolution spectra by analysing the strength of water vapour cross-correlation signals across the red optical and near-infrared wavelength ranges. Methods. A total of seven transits of the two planets were observed with the CARMENES spectrograph at the 3.5 m Calar Alto telescope. Their Doppler-shifted signals were disentangled from the telluric and stellar contributions using the detrending algorithm SYSREM. The residual spectra were subsequently cross-correlated with water vapour templates at 0.70–0.96 μm to measure the strength of the water vapour absorption bands. Results. The optical water vapour bands were detected at 5.2σ in HD 209458 b in one transit, whereas no evidence of them was found in four transits of HD 189733 b. Therefore, the relative strength of the optical water bands compared to those in the near-infrared were found to be larger in HD 209458 b than in HD 189733 b. Conclusions. We interpret the non-detection of optical water bands in the transmission spectra of HD 189733 b, compared to the detection in HD 209458 b, to be due to the presence of high-altitude hazes in the former planet, which are largely absent in the latter. This is consistent with previous measurements with the Hubble Space Telescope. We show that currently available CARMENES observations of hot Jupiters can be used to investigate the presence of haze extinction in their atmospheres.
Acceso Abierto
ESPRESSO high-resolution transmission spectroscopy of WASP-76 b
(EDP Sciences, 2021-02-19) Tabernero, H. M.; Zapatero Osorio, M. R.; Allart, R.; Borsa, F.; Casasayas Barris, N.; Demangeon, O. D. S.; Ehrenreich, D.; Lillo Box, J.; Lovis, C.; Pallé, E.; Sousa, S. G.; Rebolo, R.; Santos, Nuno C.; Pepe, Francesco; Cristiani, S.; Adibekyan, V.; Allende Prieto, C.; Alibert, Y.; Barros, S. C. C.; Bouchy, F.; Bourrier, V.; D´Odorico, V.; Dumusque, X.; Faria, J. P.; Figueira, P.; Genova Santos, R.; González Hernández, J. I.; Hojjatpanah, S.; Lo Curto, G.; Lavie, B.; Martins, C. J. A. P.; Martins, J. H. C.; Mehner, A.; Micela, G.; Molaro, P.; Nunes, Nelson J.; Poretti, E.; Seidel, J. V.; Sozzetti, A.; Suárez Mascareño, A.; Udry, S.; Aliverti, M.; Affolter, M.; Alves, D.; Amate, M.; Ávila, G.; Bandy, T.; Benz, W.; Bianco, A.; Broeg, C.; Cabral, A.; Conconi, P.; Coelho, J.; Cumani, C.; Deiries, S.; Dekker, H.; Delabre, B.; Fragoso, A.; Genoni, M.; Genolet, L.; Hughes, I.; Knudstrup, J.; Kerber, F.; Landoni, M.; Lizon, Jean Louis; Maire, C.; Manescau, A.; Di Marcantonio, P.; Mégevand, D.; Monteiro, M.; Moschetti, M.; Mueller, E.; Modigliani, A.; Oggioni, L.; Oliveira, António; Pariani, G.; Pasquini, L.; Rasilla, J. L.; Redaelli, E.; Riva, M.; Santana Tschudi, S.; Santin, P.; Santos, Pedro; Segovia, A.; Sosnowska, D.; Spanò, P.; Tenegi, F.; Iwert, O.; Zanutta, A.; Zerbi, Filippo M.; European Research Council (ERC); Fundacao para a Ciencia e a Tecnologia (FCT); Agencia Estatal de Investigación (AEI); Istituto Nazionale di Astrofisica (INAF); Cabral, A. [0000-0002-9433-871X]; Monteiro, M. J. [0000-0003-0513-8116]; Coelho, F. M. [0000-0002-4339-0550]; Faria, J. [0000-0002-6728-244X]; Santos, N. [0000-0003-4422-2919]
Aims. We report on ESPRESSO high-resolution transmission spectroscopic observations of two primary transits of the highly irradiated, ultra-hot Jupiter-sized planet, WASP-76b. We investigated the presence of several key atomic and molecular features of interest that may reveal the atmospheric properties of the planet. Methods. We extracted two transmission spectra of WASP-76b with R ≈ 140 000 using a procedure that allowed us to process the full ESPRESSO wavelength range (3800–7880 Å) simultaneously. We observed that at a high signal-to-noise ratio, the continuum of ESPRESSO spectra shows ‘wiggles’, which are likely caused by an interference pattern outside the spectrograph. To search for the planetary features, we visually analysed the extracted transmission spectra and cross-correlated the observations against theoretical spectra of different atomic and molecular species. Results. The following atomic features are detected: Li I, Na I, Mg I, Ca II, Mn I, K I, and Fe I. All are detected with a confidence level between 9.2 σ (Na I) and 2.8 σ (Mg I). We did not detect the following species: Ti I, Cr I, Ni I, TiO, VO, and ZrO. We impose the following 1 σ upper limits on their detectability: 60, 77, 122, 6, 8, and 8 ppm, respectively. Conclusions. We report the detection of Li I on WASP-76b for the first time. In addition, we confirm the presence of Na I and Fe I as previously reported in the literature. We show that the procedure employed in this work can detect features down to the level of ~0.1% in the transmission spectrum and ~10 ppm by means of a cross-correlation method. We discuss the presence of neutral and singly ionised features in the atmosphere of WASP-76b.
Acceso Abierto
Fundamental physics with ESPRESSO: Towards an accurate wavelength calibration for a precision test of the fine-structure constant
(EDP Sciences, 2021-02-19) Schmidt, T. M.; Molaro, P.; Murphy, M. T.; Lovis, C.; Cupani, G.; Cristiani, S.; Pepe, Francesco; Rebolo, R.; Santos, Nuno C.; Abreu, M.; Adibekyan, V.; Alibert, Y.; Aliverti, M.; Allart, R.; Allende Prieto, C.; Alves, D.; Baldini, V.; Broeg, C.; Cabral, A.; Calderone, G.; Cirami, R.; Coelho, J.; Coretti, I.; D´Odorico, V.; Di Marcantonio, P.; Ehrenreich, D.; Figueira, P.; Genoni, M.; Génova Santos, R.; González Hernández, J. I.; Kerber, F.; Londoni, M.; Leite, A. C. O.; Louis Lizon, J.; Lo Curto, G.; Manescau, A.; Martins, C. J. A. P.; Mégevand, D.; Mehner, A.; Micela, G.; Modigliani, A.; Monteiro, M.; Monteiro, M. J. P. F. G.; Mueller, E.; Nunes, Nelson J.; Oggioni, L.; Oliveira, António; Pariani, G.; Pasquini, L.; Redaelli, E.; Riva, M.; Santos, Pedro; Sosnowska, D.; Sousa, S. G.; Sozzetti, A.; Suárez Mascareño, A.; Udry, S.; Zapatero Osorio, M. R.; Zerbi, Filippo M.; Istituto Nazionale di Astrofisica (INAF); Australian Research Council (ARC); Swiss National Science Foundation (SNSF); Fundacao para a Ciencia e a Tecnologia (FCT); European Research Council (ERC); Schmidt, T. M. [0000-0002-4833-7273]; Molaro, P. [0000-0002-0571-4163]; Murphy, M. T. [0000-0002-7040-5498]; Cristiani, S. [0000-0002-2115-5234]; Pepe, F. A. [0000-0002-9815-773X]; Rebolo, R. [0000-0003-3767-7085]
Observations of metal absorption systems in the spectra of distant quasars allow one to constrain a possible variation of the fine-structure constant throughout the history of the Universe. Such a test poses utmost demands on the wavelength accuracy and previous studies were limited by systematics in the spectrograph wavelength calibration. A substantial advance in the field is therefore expected from the new ultra-stable high-resolution spectrograph ESPRESSO, which was recently installed at the VLT. In preparation of the fundamental physics related part of the ESPRESSO GTO program, we present a thorough assessment of the ESPRESSO wavelength accuracy and identify possible systematics at each of the different steps involved in the wavelength calibration process. Most importantly, we compare the default wavelength solution, which is based on the combination of Thorium-Argon arc lamp spectra and a Fabry-Pérot interferometer, to the fully independent calibration obtained from a laser frequency comb. We find wavelength-dependent discrepancies of up to 24 m s−1. This substantially exceeds the photon noise and highlights the presence of different sources of systematics, which we characterize in detail as part of this study. Nevertheless, our study demonstrates the outstanding accuracy of ESPRESSO with respect to previously used spectrographs and we show that constraints of a relative change of the fine-structure constant at the 10−6 level can be obtained with ESPRESSO without being limited by wavelength calibration systematics.
Acceso Abierto
Multiple water band detections in the CARMENES near-infrared transmission spectrum of HD 189733 b
(EDP Sciences, 2019-01-10) Alonso Floriano, F. J.; Sánchez López, A.; Snellen, Ignas; López Puertas, M.; Nagel, E.; Amado, P. J.; Bauer, F. F.; Caballero, J. A.; Czesla, S.; Nortmann, L.; Pallé, E.; Salz, M.; Reiners, A.; Ribas, I.; Quirrenbach, A.; Aceituno, J.; Anglada Escudé, G.; Béjar, V. J. S.; Guenther, E. W.; Henning, T.; Kaminski, A.; Kürster, M.; Lampón, M.; Lara, L. M.; Montes, D.; Morales, J. C.; Tal Or, L.; Schmitt, J. H. M. M.; Zapatero Osorio, M. R.; Zechmeister, M.; European Research Council (ERC); Ministerio de Economía y Competitividad (MINECO); Ministerio de Ciencia e Innovación (MICINN); Agencia Estatal de Investigación (AEI); Zapatero Osorio, M. R. [0000-0001-5664-2852]; Ribas, I. [0000-0002-6689-0312]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Aims. We explore the capabilities of CARMENES for characterising hot-Jupiter atmospheres by targeting multiple water bands, in particular, those at 1.15 and 1.4 μm. Hubble Space Telescope observations suggest that this wavelength region is relevant for distinguishing between hazy and/or cloudy and clear atmospheres. Methods. We observed one transit of the hot Jupiter HD 189733 b with CARMENES. Telluric and stellar absorption lines were removed using SYSREM, which performs a principal component analysis including proper error propagation. The residual spectra were analysed for water absorption with cross-correlation techniques using synthetic atmospheric absorption models. Results. We report a cross-correlation peak at a signal-to-noise ratio (S/N) of 6.6, revealing the presence of water in the transmission spectrum of HD 189733 b. The absorption signal appeared slightly blueshifted at –3.9 ± 1.3 km s−1. We measured the individual cross-correlation signals of the water bands at 1.15 and 1.4 μm, finding cross-correlation peaks at S/N of 4.9 and 4.4, respectively. The 1.4 μm feature is consistent with that observed with the Hubble Space Telescope. Conclusions. The water bands studied in this work have been mainly observed in a handful of planets from space. Being able also to detect them individually from the ground at higher spectral resolution can provide insightful information to constrain the properties of exoplanet atmospheres. Although the current multi-band detections can not yet constrain atmospheric haze models for HD 189733 b, future observations at higher S/N could provide an alternative way to achieve this aim.
Acceso Abierto
MuSCAT2 multicolour validation of TESS candidates: an ultra-short-period substellar object around an M dwarf
(EDP Sciences, 2020-01-03) Parviainen, H.; Pallé, E.; Zapatero Osorio, M. R.; Montañés Rodríguez, P.; Murgas Alcaino, F.; Narita, N.; Hidalgo Soto, D.; Béjar, V. J. S.; Korth, J.; Monelli, M.; Casasayas Barris, N.; Crouzet, N.; De Leon, J. P.; Fukui, A.; Hernández, A.; Klagyivik, P.; Kusakabe, N.; Luque, R.; Mori, M.; Nishiumi, T.; Prieto Arranz, J.; Tamura, M.; Watanabe, N.; Burke, C. J.; Charbonneau, D.; Collins, K. A.; Collins, K. I.; Conti, D.; García Soto, A.; Jenkins, J. S.; Jenkins, J. M.; Levine, A.; Li, J.; Rinehart, S.; Seager, S.; Tenenbaum, P.; Ting, E. B.; Vanderspek, R.; Vezie, M.; Winn, J. N.; Ministerio de Economía y Competitividad (MINECO); Deutsche Forschungsgemeinschaft (DFG); Agencia Estatal de Investigación (AEI); Japan Society for the Promotion of Science (JSPS); Japan Science and Technology Agency (JST); Parvianen, H. [0000-0001-5519-1391]; Monelli, M. [0000-0001-5292-6380]; Korth, J. [0000-0002-0076-6239]; Zapatero Osorio, M. R. [0000-0001-5664-2852]; Luque, R. [0000-0002-4671-2957]; Kusakabe, N. [0000-0001-9194-1268]; Collins, K. [0000-0003-2781-3207]; García Soto, A. [0000-0001-9828-3229]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Context. We report the discovery of TOI 263.01 (TIC 120916706), a transiting substellar object (R = 0.87 RJup) orbiting a faint M3.5 V dwarf (V = 18.97) on a 0.56 d orbit. Aims. We setout to determine the nature of the Transiting Exoplanet Survey Satellite (TESS) planet candidate TOI 263.01 using ground-based multicolour transit photometry. The host star is faint, which makes radial-velocity confirmation challenging, but the large transit depth makes the candidate suitable for validation through multicolour photometry. Methods. Our analysis combines three transits observed simultaneously in r′, i′, and zs bands usingthe MuSCAT2 multicolour imager, three LCOGT-observed transit light curves in g′, r′, and i′ bands, a TESS light curve from Sector 3, and a low-resolution spectrum for stellar characterisation observed with the ALFOSC spectrograph. We modelled the light curves with PYTRANSIT using a transit model that includes a physics-based light contamination component, allowing us to estimate the contamination from unresolved sources from the multicolour photometry. Using this information we were able to derive the true planet–star radius ratio marginalised over the contamination allowed by the photometry.Combining this with the stellar radius, we were able to make a reliable estimate of the absolute radius of the object. Results. The ground-based photometry strongly excludes contamination from unresolved sources with a significant colour difference to TOI 263. Furthermore, contamination from sources of the same stellar type as the host is constrained to levels where the true radius ratio posterior has a median of 0.217 and a 99 percentile of0.286. The median and maximum radius ratios correspond to absolute planet radii of 0.87 and 1.41 RJup, respectively,which confirms the substellar nature of the planet candidate. The object is either a giant planetor a brown dwarf (BD) located deep inside the so-called “brown dwarf desert”. Both possibilities offer a challenge to current planet/BD formation models and make TOI 263.01 an object that merits in-depth follow-up studies.
Acceso Abierto
Six transiting planets and a chain of Laplace resonances in TOI-178
(EDP Sciences, 2021-05-06) Leleu, A.; Alibert, Y.; Hara, N. C.; Hooton, M. J.; Wilson, T. G.; Robutel, P.; Delisle, J. B.; Laskar, J.; Hoyer, S.; Lovis, C.; Bryant, E. M.; Angerhausen, D.; Simon, A. E.; Beck, T.; Sousa, S. G.; Futyan, D.; Di Marcantonio, P.; Ehrenreich, D.; Erikson, A.; Figueira, P.; Acton, J. S.; Haldemann, J.; Thomas, N.; Boué, G.; Tilbrook, R. H.; Isaak, K.; Fridlund, M.; Gandolfi, D.; García Muñoz, Antonio; García, L. J.; Verrecchia, F.; Bárczy, T.; Charnoz, S.; Lecavelier des Etangs, A.; Guillon, M.; Goad, M. R.; González Hernández, J. I.; Guedel, M.; Zapatero Osorio, M. R.; Heng, K.; Jehin, E.; Jenkins, J. S.; Jordán, A.; Kiss, L.; Anderson, D. R.; Murray, C. A.; Anglada Escudé, G.; Fortier, A.; Barrado, David; Osborn, Hugh P.; Lam, K.; Lendl, M.; Lillo Box, J.; Lo Curto, G.; Corral Van Damme, C.; Bekkelien, A.; Gill, S.; Billot, N.; Piotto, G.; Maxted, P. F. L.; McCormac, J.; Mehner, A.; Micela, G.; Brandeker, A.; Nunes, Nelson J.; Rando, N.; Oshagh, M.; Ottensamer, R.; Pagano, I.; Pallé, E.; Cameron, A. C.; Persson, Carina; Polenta, G.; Pollacco, D.; Poretti, E.; Demangeon, O. D. S.; Sestovic, M.; Demory, B. O.; Magrin, D.; Di Persio, G.; Sozzetti, A.; Ragazzoni, R.; Ratti, F.; Rauer, H.; Raynard, L.; Fossati, L.; Molaro, P.; Nascimbeni, V.; Triaud, A.; Ribas, I.; Santos, Nuno C.; Scandariato, G.; Schneider, J.; Gillen, E.; Smith, A. M. S.; Steller, M.; Suárez Mascareño, A.; Szabó, Gy. M.; Ségransan, D.; Günther, M. N.; Ducrot, E.; Henderson, B.; Pozuelos, F. J.; Hogan, A. E.; Adibekyan, V.; Thompson, S.; Turner, O.; Udry, S.; Van Grootel, V.; Olofsson, G.; Kristiansen, M. H.; Rebolo, R.; Lavie, B.; Barros, S. C. C.; Vines, J. I.; Walton, N. A.; West, R. G.; Wheatley, Peter; Martins, C. J. A. P.; Delrez, L.; Bonfanti, A.; Allart, R.; Allende Prieto, C.; Alonso, R.; Alves, D.; Moyaro, M.; Asquier, J.; Baumjohann, W.; Bayliss, D.; Beck, M.; Pedersen, P. P.; Chamberlain, S.; Pepe, Francesco; Venus, H.; Peter, G.; Correia, A. C. M.; Benz, W.; Bonfils, X.; Bouchy, F.; Bourrier, V.; Queloz, D.; Wolter, D.; Cabrera, J.; Dumusque, X.; Broeg, C.; Buder, M.; Burdanov, A.; Burleigh, M. R.; Reimers, C.; Cooke, B. F.; Cristiani, S.; Damasso, M.; Davies, M. B.; Deleuil, M.; Sebastian, D.; Alvarez, M. [0000-0002-6786-2620]; Carrasco Martínez, J. M. [0000-0002-3029-5853]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Determining the architecture of multi-planetary systems is one of the cornerstones of understanding planet formation and evolution. Resonant systems are especially important as the fragility of their orbital configuration ensures that no significant scattering or collisional event has taken place since the earliest formation phase when the parent protoplanetary disc was still present. In this context, TOI-178 has been the subject of particular attention since the first TESS observations hinted at the possible presence of a near 2:3:3 resonant chain. Here we report the results of observations from CHEOPS, ESPRESSO, NGTS, and SPECULOOS with the aim of deciphering the peculiar orbital architecture of the system. We show that TOI-178 harbours at least six planets in the super-Earth to mini-Neptune regimes, with radii ranging from 1.152−0.070+0.073 to 2.87−0.13+0.14 Earth radii and periods of 1.91, 3.24, 6.56, 9.96, 15.23, and 20.71 days. All planets but the innermost one form a 2:4:6:9:12 chain of Laplace resonances, and the planetary densities show important variations from planet to planet, jumping from 1.02−0.23+0.28 to 0.177−0.061+0.055 times the Earth’s density between planets c and d. Using Bayesian interior structure retrieval models, we show that the amount of gas in the planets does not vary in a monotonous way, contrary to what one would expect from simple formation and evolution models and unlike other known systems in a chain of Laplace resonances. The brightness of TOI-178 (H = 8.76 mag, J = 9.37 mag, V = 11.95 mag) allows for a precise characterisation of its orbital architecture as well as of the physical nature of the six presently known transiting planets it harbours. The peculiar orbital configuration and the diversity in average density among the planets in the system will enable the study of interior planetary structures and atmospheric evolution, providing important clues on the formation of super-Earths and mini-Neptunes.
Acceso Abierto
The atmosphere of HD 209458b seen with ESPRESSO No detectable planetary absorptions at high resolution
(EDP Sciences, 2021-03-02) Casasayas Barris, N.; Pallé, E.; Strangret, M.; Bourrier, V.; Tabernero, H. M.; Yan, F.; Borsa, F.; Allart, R.; Zapatero Osorio, M. R.; Lovis, C.; Sousa, S. G.; Chen, G.; Oshagh, M.; Santos, Nuno C.; Pepe, Francesco; Rebolo, R.; Molaro, P.; Cristiani, S.; Adibekyan, V.; Alibert, Y.; Allende Prieto, C.; Bouchy, F.; Demangeon, O. D. S.; Di Marcantonio, P.; D´Odorico, V.; Ehrenreich, D.; Figueira, P.; Génova Santos, R.; González Hernández, J. I.; Lavie, B.; Lillo Box, J.; Lo Curto, G.; Martins, C. J. A. P.; Mehner, A.; Micela, G.; Nunes, Nelson J.; Poretti, E.; Sozzetti, A.; Suárez Mascareño, A.; Udry, S.; National Natural Science Foundation of China (NSFC); Deutsche Forschungsgemeinschaft (DFG); European Research Council (ERC); Fundacao para a Ciencia e a Tecnologia (FCT); Istituto Nazionale di Astrofisica (INAF); Agencia Estatal de Investigación (AEI); Swiss National Science Foundation (SNSF); Yan, F. [0000-0001-9585-9034]; Sozzetti, A. [0000-0002-7504-365X]; Nunes, N. [0000-0002-3837-6914]; Santos, N. [0000-0003-4422-2919]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
We observed two transits of the iconic gas giant HD 209458b between 380 and 780 nm, using the high-resolution ESPRESSO spectrograph. The derived planetary transmission spectrum exhibits features at all wavelengths where the parent star shows strong absorption lines, for example, Na I, Mg I, Fe I, Fe II, Ca I, V I, Hα, and K I. We interpreted these features as the signature of the deformation of the stellar line profiles due to the Rossiter-McLaughlin effect, combined with the centre-to-limb effects on the stellar surface, which is in agreement with similar reports recently presented in the literature. We also searched for species that might be present in the planetary atmosphere but not in the stellar spectra, such as TiO and VO, and obtained a negative result. Thus, we find no evidence of any planetary absorption, including previously reported Na I, in the atmosphere of HD 209458b. The high signal-to-noise ratio in the transmission spectrum (~1700 at 590 nm) allows us to compare the modelled deformation of the stellar lines in assuming different one-dimensional stellar atmospheric models. We conclude that the differences among various models and observations remain within the precision limits of the data. However, the transmission light curves are better explained when the centre-to-limb variation is not included in the computation and only the Rossiter-McLaughlin deformation is considered. This demonstrates that ESPRESSO is currently the best facility for spatially resolving the stellar surface spectrum in the optical range using transit observations and carrying out empirical validations of stellar models.
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.; Chontos, A.; Esparza Borges, E.; Evans, P.; Ciardi, D. R.; Flowers, E. E.; Fukui, A.; Collins, K. I.; Furlan, E.; Gaidos, E.; Crane, J. D.; Giacalone, S.; Gillon, M.; Dragomir, D.; Gorjian, V.; Hellier, C.; Feng, F.; Howard, A. W.; Howell, Steve B.; Fulton, B.; Isaacson, I.; Geneser, C.; Jensen, E. L. N.; Kaminski, A.; Gonzales, E.; Kawauchi, K.; Kielkopf, J. F.; Hidalgo, D.; Kosiarek, M. R.; Kreidberg, L.; Huber, D.; Lafarga, M.; Livingston, J.; Jehin, E.; Mann, A. W.; Madrigal Aguado, A.; Kane, S. R.; Mocnik, T.; Morales, J. C.; Klahr, H.; Murgas Alcaino, F.; Kürster, M.; Narita, N.; Nowak, G.; Louie, D.; Parviainen, H.; Passegger, V. M.; Matson, R. A.; Pozuelos, F. J.; Quirrenbach, A.; Muirhead, P. S.; Ribas, I.; Robertson, P.; Nandakumar, S.; Rose, M. E.; Roy, A.; Oshagh, M.; Schlieder, Joshua; Shectman, S.; Pollacco, D.; Senavci, H. V.; Reefe, M.; Twicken, J. D.; Villaseñor, J. N.; Rodríguez López, C.; Weiss, L. M.; Wittrock, J.; Schweitzer, A.; Zohrabi, F.; Cale, B.; Tanner, A.; Schlecker, M.; Lillo Box, J.; Teske, J.; Lalitha, S.; Reiners, A.; Wang, S. X.; Bitsch, B.; Zapatero Osorio, M. R.; Yilmaz, M.; Ricker, George; Caballero, J. A.; Latham, D. W.; Seager, S.; Zechmeister, M.; Jenkins, J. M.; Aceituno, J.; Soubkiou, A.; Barkaoui, K.; Chaturvedi, P.; Hatzes, Artie; Batalha, N. M.; Bauer, F. F.; Vanderspek, R.; Benkhaldoun, Z.; Beichman, C.; Winn, J. N.; Butler, R. P.; Caldwell, D. A.; Amado, P. J.; Christianesen, J. L.; Barbieri, M.; Cifuentes, C.; Collins, K. A.; Benneke, B.; Combs, D.; Cortés Contreras, M.; Burt, J.; Daylan, T.; Chintada, A.; 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 widest broadband transmission spectrum (0.38–1.71 μm) of HD 189733b from ground-based chromatic Rossiter–McLaughlin observations
(EDP Sciences, 2020-11-03) Oshagh, M.; Bauer, F. F.; Lafarga, M.; Molaverdikhani, K.; Amado, P. J.; Nortmann, L.; Reiners, A.; Guzmán Mesa, A.; Pallé, E.; Nagel, E.; Caballero, J. A.; Casasayas Barris, N.; Claret, A.; Czesla, S.; Galadí Enríquez, D.; Henning, T.; Khalafinejad, S.; López Puertas, M.; Montes, D.; Quirrenbach, A.; Ribas, I.; Strangret, M.; Yan, F.; Zapatero Osorio, M. R.; Zechmeister, M.; Deutsche Forschungsgemeinschaft (DFG); European Regional Development Fund (ERDF); Agencia Estatal de Investigación (AEI); Oshagh, M. [0000-0002-0715-8789]; Guzman Mesa, A. [0000-0001-5762-0276]; 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
Multiband photometric transit observations (spectro-photometric) have been used mostly so far to retrieve broadband transmission spectra of transiting exoplanets in order to study their atmospheres. An alternative method was proposed, and has only been used once, to recover broadband transmission spectra using chromatic Rossiter–McLaughlin observations. We use the chromatic Rossiter–McLaughlin technique on archival and new observational data obtained with the HARPS and CARMENES instruments to retrieve transmission spectra of HD 189733b. The combined results cover the widest retrieved broadband transmission spectrum of an exoplanet obtained from ground-based observation. Our retrieved spectrum in the visible wavelength range shows the signature of a hazy atmosphere, and also includes an indication for the presence of sodium and potassium. These findings all agree with previous studies. The combined visible and near-infrared transmission spectrum exhibits a strong steep slope that may have several origins, such as a super-Rayleigh slope in the atmosphere of HD 189733b, an unknown systematic instrumental offset between the visible and near-infrared, or a strong stellar activity contamination. The host star is indeed known to be very active and might easily generate spurious features in the retrieved transmission spectra. Using our CARMENES observations, we assessed this scenario and place an informative constraint on some properties of the active regions of HD 189733. We demonstrate that the presence of starspots on HD 189733 can easily explain our observed strong slope in the broadband transmission spectrum.
Acceso Abierto
TOI-519 b: A short-period substellar object around an M dwarf validated using multicolour photometry and phase curve analysis
(EDP Sciences, 2021-01-15) Parviainen, H.; Pallé, E.; Zapatero Osorio, M. R.; Nowak, G.; Fukui, A.; Murgas Alcaino, F.; Narita, N.; Stassun, K. G.; Livingston, J.; Collins, K. A.; Hidalgo Soto, D.; Béjar, V. J. S.; Korth, J.; Monelli, M.; Montañés Rodríguez, P.; Casasayas Barris, N.; Chen, G.; Crouzet, N.; De Leon, J. P.; Hernández, A.; Kawauchi, K.; Klagyivik, P.; Kusakabe, N.; Luque, R.; Mori, M.; Nishiumi, T.; Prieto Arranz, J.; Tamura, M.; Watanabe, N.; Gan, T.; Collins, K. I.; Jensen, E. L. N.; Barclay, T.; Doty, J. P.; Jenkins, J. M.; Latham, D. W.; Paegert, M.; Ricker, George; Rodríguez, D. R.; Seager, S.; Shporer, A.; Vanderspek, R.; Villaseñor, J. N.; Winn, J. N.; Wohler, B.; Wong, I.; Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI); Japan Society for the Promotion of Science (JSPS); Deutsche Forschungsgemeinschaft (DFG); Monelli, M. [0000-0001-5292-6380]; Collins, K. [0000-0003-2781-3207]; Paegert, M. [0000-0001-8120-7457]; Luque, R. [0000-0002-4671-2957]
Context. We report the discovery of TOI-519 b (TIC 218795833), a transiting substellar object (R = 1.07 RJup) orbiting a faint M dwarf (V = 17.35) on a 1.26 d orbit. Brown dwarfs and massive planets orbiting M dwarfs on short-period orbits are rare, but more have already been discovered than expected from planet formation models. TOI-519 is a valuable addition to this group of unlikely systems, and it adds towards our understanding of the boundaries of planet formation. Aims. We set out to determine the nature of the Transiting Exoplanet Survey Satellite (TESS) object of interest TOI-519 b. Methods. Our analysis uses a SPOC-pipeline TESS light curve from Sector 7, multicolour transit photometry observed with MuSCAT2 and MuSCAT, and transit photometry observed with the LCOGT telescopes. We estimated the radius of the transiting object using multicolour transit modelling, and we set upper limits for its mass, effective temperature, and Bond albedo using a phase curve model that includes Doppler boosting, ellipsoidal variations, thermal emission, and reflected light components. Results. TOI-519 b is a substellar object with a radius posterior median of 1.07 RJup and 5th and 95th percentiles of 0.66 and 1.20 RJup, respectively, where most of the uncertainty comes from the uncertainty in the stellar radius. The phase curve analysis sets an upper effective temperature limit of 1800 K, an upper Bond albedo limit of 0.49, and a companion mass upper limit of 14 MJup. The companion radius estimate combined with the Teff and mass limits suggests that the companion is more likely a planet than a brown dwarf, but a brown-dwarf scenario is a priori more likely given the lack of known massive planets in ≈ 1 day orbits around M dwarfs with Teff < 3800 K, and given the existence of some (but few) brown dwarfs.
Acceso Abierto
WASP-127b: a misaligned planet with a partly cloudy atmosphere and tenuous sodium signature seen by ESPRESSO
(EDP Sciences, 2020-12-16) Allart, R.; Pino, L.; Lovis, C.; Sousa, S. G.; Casasayas Barris, N.; Zapatero Osorio, M. R.; Cretignier, M.; Pallé, E.; Pepe, Francesco; Cristiani, S.; Rebolo, R.; Santos, Nuno C.; Borsa, F.; Bourrier, V.; Demangeon, O. D. S.; Ehrenreich, D.; Lavie, B.; Lendl, M.; Lillo Box, J.; Micela, G.; Oshagh, M.; Sozzetti, A.; Tabernero, H. M.; Adibekyan, V.; Allende Prieto, C.; Alibert, Y.; Amate, M.; Benz, W.; Bouchy, F.; Cabral, A.; Dekker, H.; D´Odorico, V.; Di Marcantonio, P.; Dumusque, X.; Figueira, P.; Genova Santos, R.; González Hernández, J. I.; Lo Curto, G.; Manescau, A.; Martins, C. J. A. P.; Mégevand, D.; Mehner, A.; Molaro, P.; Nunes, Nelson J.; Poretti, E.; Riva, M.; Suárez Mascareño, A.; Udry, S.; Zerbi, Filippo M.; Swiss National Science Foundation (SNSF); European Research Council (ERC); Fundacao para a Ciencia e a Tecnologia (FCT); Istituto Nazionale di Astrofisica (INAF)
Context. The study of exoplanet atmospheres is essential for understanding the formation, evolution, and composition of exoplanets. The transmission spectroscopy technique is playing a significant role in this domain. In particular, the combination of state-of-the-art spectrographs at low- and high-spectral resolution is key to our understanding of atmospheric structure and composition. Aims. We observed two transits of the close-in sub-Saturn-mass planet, WASP-127b, with ESPRESSO in the frame of the Guaranteed Time Observations Consortium. We aim to use these transit observations to study the system architecture and the exoplanet atmosphere simultaneously. Methods. We used the Reloaded Rossiter-McLaughlin technique to measure the projected obliquity lambda and the projected rotational velocity nu(eq).sin(i(*)). We extracted the high-resolution transmission spectrum of the planet to study atomic lines. We also proposed a new cross-correlation framework to search for molecular species and we applied it to water vapor. Results. The planet is orbiting its slowly rotating host star (nu(eq).sin(i(*)) = 0.53(-0.05)(+0.07) km s(-1)) on a retrograde misaligned orbit (lambda = -128.41(+5.60)degrees(-5.46)). We detected the sodium line core at the 9-sigma confidence level with an excess absorption of 0.34 +/- 0.04%, a blueshift of 2.74 +/- 0.79 km s(-1), and a full width at half maximum of 15.18 +/- 1.75 km s(-1). However, we did not detect the presence of other atomic species but set upper limits of only a few scale heights. Finally, we put a 3-sigma upper limit on the average depth of the 1600 strongest water lines at equilibrium temperature in the visible band of 38 ppm. This constrains the cloud-deck pressure between 0.3 and 0.5 mbar by combining our data with low-resolution data in the near-infrared and models computed for this planet. Conclusions. WASP-127b, with an age of about 10 Gyr, is an unexpected exoplanet by its orbital architecture but also by the small extension of its sodium atmosphere (similar to 7 scale heights). ESPRESSO allows us to take a step forward in the detection of weak signals, thus bringing strong constraints on the presence of clouds in exoplanet atmospheres. The framework proposed in this work can be applied to search for molecular species and study cloud-decks in other exoplanets.