Persona: Zapatero Osorio, María Rosa
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Centro de Astrobiologia
El Centro de Astrobiología (CAB) es un centro mixto de investigación en astrobiología, dependiente tanto del Instituto Nacional de Técnica Aeroespacial (INTA) como del Consejo Superior de Investigaciones Científicas (CSIC).
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Publicación 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, María Rosa; 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-2017-0709Multiband 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.Publicación Acceso Abierto Revisiting Proxima with ESPRESSO(EDP Sciences, 2020-07-13) Suárez Mascareño, A.; Faria, J. P.; Figueira, P.; Lovis, C.; Damasso, M.; González Hernández, J. I. ; Rebolo, R.; Cristiani, S.; Pepe, Francesco ; Santos, Nuno C. ; Zapatero Osorio, María Rosa; Adibekyan, Vardan; Hojjatpanah, S.; Sozzetti, A.; Murgas Alcaino, F. ; Abreu, M.; Affolter, M.; Alibert, Yann; Aliverti, M.; Allart, R.; Allende Prieto, C.; Alves, D.; Amate, M.; Ávila, G.; Baldini, V.; Bandi, T.; Barros, S. C. C.; Bianco, A.; Benz, W.; Bouchy, F. ; Broeg, C.; Cabral, A.; Calderone, G.; Cirami, R.; Coelho, J.; Conconi, P.; Coretti, I.; Cumani, C.; Cupani, G.; D´Odorico, V.; Deiries, S.; Delabre, B.; Di Marcantonio, P.; Dumusque, X.; Ehrenreich, D.; Fragoso, A.; Genolet, L.; Genoni, M.; Génova Santos, R.; Hughes, I.; Iwert, O.; Kerber, F.; Knudstrup, J.; Landoni, M.; Lavie, B.; Lillo Box, J.; Lizon, Jean Louis; Lo Curto, G.; Maire, C.; Manescau, A.; Martins, C. J. A. P.; Mégevand, D.; Mehner, A.; Micela, G.; Modigliani, A.; Molaro, P.; Monteiro, M. A.; Monteiro, M. J. P. F. G.; Moschetti, M.; Mueller, E.; Nunes, Nelson J.; Oggioni, L.; Oliveira, António; Pallé, E. ; Pariani, G.; Pasquini, L.; Poretti, E.; Rasilla, J. L.; Redaelli, E.; Riva, M.; Santana Tschudi, S.; Santin, P.; Santos, Pedro; Segovia, A.; Sosnowska, D.; Sousa, S. G.; Spanò, P.; Tenegi, F.; Udry, S.; Zanutta, A.; Zerbi, Filippo M.; Agencia Estatal de Investigación (AEI); Ministerio de Economía y Competitividad (MINECO); Swiss National Science Foundation (SNSF); Fundacao para a Ciencia e a Tecnologia (FCT); European Research Council (ERC); Lillo Box, J. [0000-0003-3742-1987]; Faria, J. [0000-0002-6728-244X]; Nunes, N. J. [0000-0002-3837-6914]; Molaro, P. [0000-0002-0571-4163]; Mascareño, A. S. [0000-0002-3814-5323]; Cabral, A. [0000-0002-9433-871X]; Monteiro, M. J. P. F. G. [0000-0003-0513-8116]; Redaelli, E. M. A. [0000-0001-8185-2122]; Barros, S. [0000-0003-2434-3625]; Santos, N. [0000-0003-4422-2919]; Abreu, M. [0000-0002-0716-9568]; Coretti, I. [0000-0001-9374-3249]; Sozzetti, A. [0000-0002-7504-365X]; Adibekyan, V. [0000-0002-0601-6199]; Monteiro, M. [0000-0001-5644-0898]; Damasso, M. [0000-0001-9984-4278]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737Context. The discovery of Proxima b marked one of the most important milestones in exoplanetary science in recent years. Yet the limited precision of the available radial velocity data and the difficulty in modelling the stellar activity calls for a confirmation of the Earth-mass planet. Aims. We aim to confirm the presence of Proxima b using independent measurements obtained with the new ESPRESSO spectrograph, and refine the planetary parameters taking advantage of its improved precision. Methods. We analysed 63 spectroscopic ESPRESSO observations of Proxima (Gl 551) taken during 2019. We obtained radial velocity measurements with a typical radial velocity photon noise of 26 cm s−1. We combined these data with archival spectroscopic observations and newly obtained photometric measurements to model the stellar activity signals and disentangle them from planetary signals in the radial velocity (RV) data. We ran a joint Markov chain Monte Carlo analysis on the time series of the RV and full width half maximum of the cross-correlation function to model the planetary and stellar signals present in the data, applying Gaussian process regression to deal with the stellar activity signals. Results. We confirm the presence of Proxima b independently in the ESPRESSO data and in the combined ESPRESSO+ HARPS+UVES dataset. The ESPRESSO data on its own shows Proxima b at a period of 11.218 ± 0.029 days, with a minimum mass of 1.29 ± 0.13 M⊕. In the combined dataset we measure a period of 11.18427 ± 0.00070 days with a minimum mass of 1.173 ± 0.086 M⊕. We get a clear measurement of the stellar rotation period (87 ± 12 d) and its induced RV signal, but no evidence of stellar activity as a potential cause for the 11.2 days signal. We find some evidence for the presence of a second short-period signal, at 5.15 days with a semi-amplitude of only 40 cm s−1. If caused by a planetary companion, it would correspond to a minimum mass of 0.29 ± 0.08 M⊕. We find that forthe case of Proxima, the full width half maximum of the cross-correlation function can be used as a proxy for the brightness changes and that its gradient with time can be used to successfully detrend the RV data from part of the influence of stellar activity. The activity-induced RV signal in the ESPRESSO data shows a trend in amplitude towards redder wavelengths. Velocities measured using the red end of the spectrograph are less affected by activity, suggesting that the stellar activity is spot dominated. This could be used to create differential RVs that are activity dominated and can be used to disentangle activity-induced and planetary-induced signals. The data collected excludes the presence of extra companions with masses above 0.6 M⊕ at periods shorter than 50 days.Publicación 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, Jose A.; Sanz-Forcada, Jorge; Lara, L. M.; Nagel, E.; Yan, F.; Alonso Floriano, F. J.; Amado, P. J.; Chen, G.; Carlos, Cifuentes; 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, María Rosa; 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-2017-0737High 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.Publicación Acceso Abierto USco1621 B and USco1556 B: Two wide companions at the deuterium-burning mass limit in Upper Scorpius(EDP Sciences, 2020-01-24) Chinchilla, P.; Béjar, V. J. S.; Lodieu, N.; Gauza, B.; Zapatero Osorio, María Rosa; Rebolo, R.; Pérez Garrido, A.; Álvarez, C.; Manjavacas, E.; European Southern Observatory (ESO); Agencia Estatal de Investigación (AEI); Ministerio de Economía y Competitividad (MINECO); Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT); Chinchilla, P. [0000-0002-3031-4911]; Béjar, V. J. S. [0000-0002-5086-4232]; Lodieu, N. [0000-0002-3612-8968]; Gauza, B. [0000-0001-5452-2056]; Zapatero Osorio, M. R. [0000-0001-5664-2852]; Rebolo, R. [0000-0003-3767-7085]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737Aims. Our objective is to identify analogues of gas giant planets, but located as companions at wide separations of very young stars. The main purpose is to characterise the binarity frequency and the properties of these substellar objects, and to elucidate their early evolutionary stages. Methods. To identify these objects, we cross correlated the Visible and Infrared Survey Telescope for Astronomy Hemisphere Survey and the United Kingdom Infrared Telescope Infrared Deep Sky Survey Galactic Clusters Survey catalogues to search for common proper motion companions to 1195 already known members of Upper Scorpius (USco; age ~5–10 Myr, distance ~145 pc). We present the discovery and spectroscopic characterisation of two very wide substellar companions of two early-M stars in Upper Scorpius: USco1621 B and USco1556 B. We obtained optical and near-infrared low-resolution spectroscopy of the candidates to characterise their spectral energy distribution and confirm their youth and membership to the association. We also acquired adaptive optics images of the primaries and secondaries to search for signs of binarity and close companions. Results. By comparison with field dwarfs and other young members of USco, we determined a spectral type of M8.5 in the optical for both companions, along with L0 and L0.5 in the near-infrared for USco1621 B and USco1556 B, respectively. The spectra of the two companions show evident markers of youth, such as weak alkaline Na I and K I lines, along with the triangular shape of the H-band. The comparison with theoretical evolutionary models gives estimated masses of 0.015 ± 0.002 and 0.014 ± 0.002 M⊙, with temperatures of 2270 ± 90 and 2240 ± 100 K, respectively. The physical separations between the components of both systems are 2880 ± 20 and 3500 ± 40 AU for USco1621 and USco1556 systems, respectively. We did not find any additional close companion in the adaptive optics images. The probability that the two secondaries are physically bound to their respective primaries, and not chance alignments of USco members, is 86%, and the probability that none of them are physically related is 1.0%.Publicación Acceso Abierto Spectral library of age-benchmark low-mass stars and brown dwarfs(Oxford Academics: Oxford University Press, 2020-12-27) Manjavacas, E.; Lodieu, N.; Béjar, V. J. S.; Zapatero Osorio, María Rosa; Boudreault, S.; Bonnefoy, M.; Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI); Manjavacas, E. [0000-0003-0192-6887]; Zapatero Osorio, M. R. [0000-0001-5664-2852]In recent years, some extremely red brown dwarfs have been discovered. They were believed to have a low surface gravity, but many of their spectral characteristics are similar to those of high-surface-gravity brown dwarfs, showing that the spectral characteristics of young brown dwarfs are poorly understood. We aim to test surface-gravity indicators in late-M and early-L brown dwarf spectra using data obtained with the X-shooter spectrograph at the Very Large Telescope. We select a benchmark sample of brown dwarf members of Chamaeleon I (∼2 Myr), Upper Scorpius (5−10 Myr), the Pleiades (132 ± 27 Myr) and Praesepe (590−790 Myr) with well-constrained ages and similar metallicities. We provide a consistent spectral classification of the sample in the optical and in the near-infrared. We measure the equivalent widths of their alkali lines, finding that they have a moderate correlation with age, especially for objects with spectral types M8 and later. We use spectral indices defined in the literature to estimate surface gravity, finding that their gravity assignment is accurate for 75 per cent of our sample. We investigate the correlation between red colour and age, finding that after ∼10 Myr, the colour does not change significantly for our sample with spectral types M6.0–L3.0. In this case, the red colours might be associated with circumstellar discs, ring structures, extinction, or viewing angle. Finally, we calculate the bolometric luminosity, and J and K bolometric corrections for our sample. We find that six objects are overluminous compared with other members of the same association. These objects are flagged as binary candidates by the Gaia survey.Publicación Acceso Abierto The CARMENES search for exoplanets around M dwarfs: A super-Earth planet orbiting HD 79211 (GJ 338 B)(EDP Sciences, 2020-05-27) González Álvarez, E.; Zapatero Osorio, María Rosa; Caballero, J. A.; Sanz-Forcada, Jorge; Béjar, V. J. S.; González Cuesta, L.; Dreizler, S.; Bauer, F. F.; Rodríguez, E.; Tal Or, L.; Zechmeister, M.; Montes, D.; López González, M. J.; Ribas, I.; Reiners, A.; Quirrenbach, A.; Amado, P. J.; Anglada Escudé, G.; Azzaro, M.; Cortés Contreras, M.; Hatzes, Artie ; Henning, T.; Jeffers, S. V.; Kaminski, A.; Kürster, M.; Lafarga, M.; Morales, J. C.; Pallé, E. ; Perger, M.; Schmitt, H. M. M.; Agencia Estatal de Investigación (AEI); González Álvarez, E. https://orcid.org/0000-0002-4820-2053; Zapatero Osorio, M. R.https://orcid.org/0000-0001-5664-2852; Caballero, J. A. https://orcid.org/0000-0002-7349-1387; López González, M. J. https://orcid.org/0000-0002-0011-3086; 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-2017-0709Aims. We report on radial velocity time series for two M0.0 V stars, GJ 338 B and GJ 338 A, using the CARMENES spectrograph, complemented by ground-telescope photometry from Las Cumbres and Sierra Nevada observatories. We aim to explore the presence of small planets in tight orbits using the spectroscopic radial velocity technique. Methods. We obtained 159 and 70 radial velocity measurements of GJ 338 B and A, respectively, with the CARMENES visible channel between 2016 January and 2018 October. We also compiled additional relative radial velocity measurements from the literature and a collection of astrometric data that cover 200 a of observations to solve for the binary orbit. Results. We found dynamical masses of 0.64 ± 0.07 M° for GJ 338 B and 0.69 ± 0.07 M° for GJ 338 A. The CARMENES radial velocity periodograms show significant peaks at 16.61 ± 0.04 d (GJ 338 B) and 16.3-1.3+3.5 d (GJ 338 A), which have counterparts at the same frequencies in CARMENES activity indicators and photometric light curves. We attribute these to stellar rotation. GJ 338 B shows two additional, significant signals at 8.27 ± 0.01 and 24.45 ± 0.02 d, with no obvious counterparts in the stellar activity indices. The former is likely the first harmonic of the star's rotation, while we ascribe the latter to the existence of a super-Earth planet with a minimum mass of 10.27-1.38+1.47 M⊕ orbiting GJ 338 B. We have not detected signals of likely planetary origin around GJ 338 A. Conclusions. GJ 338 Bb lies inside the inner boundary of the habitable zone around its parent star. It is one of the least massive planets ever found around any member of stellar binaries. The masses, spectral types, brightnesses, and even the rotational periods are very similar for both stars, which are likely coeval and formed from the same molecular cloud, yet they differ in the architecture of their planetary systems. © ESO 2020.Publicación 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, María Rosa; 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.Publicación Acceso Abierto Six transiting planets and a chain of Laplace resonances in TOI-178(EDP Sciences, 2021-05-06) Leleu, A.; Alibert, Yann; Hara, Nathan 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.; Sebastian, D.; Zapatero Osorio, María Rosa; 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, Vardan; 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, Xavier; 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.; 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-2017-0737Determining 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.Publicación Acceso Abierto ESPRESSO mass determination of TOI-263b: an extreme inhabitant of the brown dwarf desert(EDP Sciences, 2021-06-04) Pallé, E. ; Luque, R. ; Zapatero Osorio, María Rosa; Parviainen, H.; Ikoma, M.; Tabernero, H. M. ; Zechmeister, M.; Mustill, A. J.; Béjar, V. J. S.; Narita, N.; Agencia Estatal de Investigación (AEI), European Research Council; Fundacao para a Ciencia e a Tecnologia (FCT); National Aeronautics and Space Administration (NASA); National Science Foundation (NSF); Japan Society for the Promotion of Science (KAKENHI)The TESS mission has reported a wealth of new planetary systems around bright and nearby stars amenable for detailed characterizations of planet properties and atmospheres. However, not all interesting TESS planets orbit around bright host stars. TOI-263 b is a validated ultra-short-period substellar object in a 0.56-day orbit around a faint (V = 18.97) M 3.5 dwarf star. The substellar nature of TOI-263 b was explored using multicolor photometry: a true radius of 0.87 ± 0.21 RJ was determined, establishing TOI-263 b ’s nature as somewhere between an inflated Neptune and a brown dwarf. The orbital period-radius parameter space occupied by TOI-263 b is quite unique, which prompted a further characterization of its true nature. Here, we report radial velocity measurements of TOI-263 obtained with three VLT units and the ESPRESSO spectrograph to retrieve the mass of TOI-263 b. We find that TOI-263 b is a brown dwarf with a mass of 61.6 ± 4.0 MJup. Additionally, the orbital period of the brown dwarf is found to be synchronized with the rotation period of the host star, and the system is found to be relatively active, possibly revealing a star–brown dwarf interaction. All these findings suggest that the system’s formation history might be explained via disk fragmentation and a later migration to close-in orbits. If the system is found to be unstable, TOI-263 will be an excellent target to test the migration mechanisms before the brown dwarf becomes “engulfed” by its parent star.Publicación Acceso Abierto A transiting rocky super-Earth and a non-transiting sub-Neptune orbiting the M dwarf TOI-771(EDP Sciences, 2025-06-20) Lacedelli, G.; Pallé, E.; Davis, Yasmin T.; Luque, R. ; Morello, G.; Tabernero, H. M.; Zapatero Osorio, María Rosa; Pozuelos, F. J.; Jankowski, Dawid; Nowak, G.; Murgas Alcaino, F.; Orell-Miquel, Jaume; Akana Murphy, Joseph M.; Barkaoui, K.; Charbonneau, D.; Dransfield, G.; Ducrot, E.; Geraldía González, Samuel; Irwin, J.; Jehin, E.; Osborne, H. L. M.; Pedersen, P. P.; Rackham, B. V. , P. P.; Scott, Madison Grace; Timmermans, M.; Triaud, A.; Van Eylen, V.; Agencia Estatal de Investigación (AEI); National Aeronautics and Space Administration (NASA); European Research Council (ERC); European Commission (EC); Science and Technology Facilities Council (STFC); Belgian National Fund for Scientific Research (FNRS); National Science Foundation (NSF)[Context] The origin and evolution of the sub-Neptune population is a highly debated topic in the exoplanet community. With the advent of JWST, atmospheric studies can now put unprecedented constraints on the internal composition of this population. In this context, the THIRSTEE project aims to investigate the population properties of sub-Neptunes with a comprehensive and demographic approach, providing a homogeneous sample of precisely characterised sub-Neptunes across stellar spectral types. [Aims] We present here the precise characterisation of the planetary system orbiting one of the THIRSTEE M-dwarf targets, TOI-771 (d = 25 pc, V = 14.9 mag), known to host one planet, TOI-771 b, which has been statistically validated using TESS observations. [Methods] We use TESS, SPECULOOS, TRAPPIST, and M-Earth photometry together with 31 high-precision ESPRESSO radial velocities to derive the orbital parameters and investigate the internal composition of TOI-771 b, as well as exploring the presence of additional companions in the system. [Results] We derived the precise mass and radius for TOI-771 b, a super-Earth with Rb = 1.36 ± 0.10 R⊕ and Mb = 2.47−0.31+0.32M⊕ orbiting every 2.3 days around its host star. Its composition is consistent with an Earth-like planet, and it adds up to the rocky population of subNeptunes lying below the density gap identified around M dwarfs. With a ∼ 13% precision in mass, a∼ 7% radius precision, and a warm equilibrium temperature of Teq =543K, TOI-771 b is a particularly interesting target for atmospheric characterisation with JWST, and it is indeed one of the targets under consideration for the Rocky World DDT programme. Additionally, we discover the presence of a second, non-transiting planet in the system, TOI-771 c, with a period of 7.61 days and a minimum mass of Mp sin i = 2.87−0.38+0.41M⊕. Even though the inclination is not directly constrained, the planet likely belongs to the temperate sub-Neptune population, with an equilibrium temperature of ∼ 365K.
