Examinando por Autor "Correia, A. C. M."

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Acceso Abierto
Planetary system LHS 1140 revisited with ESPRESSO and TESS
(EDP Sciences, 2020-10-15) Lillo Box, J.; Figueira, P.; Leleu, A.; Acuña, L.; Faria, J. P.; Harada, N.; Santos, Nuno C. ; Correia, A. C. M.; Robutel, P.; Deleuil, M.; Barrado, David; Sousa, S. G.; Bonfils, Xavier; Mousis, O.; Almenara, J. M.; Astudillo Defru, N.; Marcq, E.; Udry, S.; Lovis, C.; Pepe, Francesco ; Fundacao para a Ciencia e a Tecnologia (FCT); Agencia Estatal de Investigación (AEI); Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT); European Commission (EC); Faria, J. [0000-0002-6728-244X]; Correia, A. C. M. [0000-0002-8946-8579]; Leleu, A. [0000-0003-2051-7974]; Lillo Box, J. [0000-0003-3742-1987]; 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
Context. LHS 1140 is an M dwarf known to host two transiting planets at orbital periods of 3.77 and 24.7 days. They were detected with HARPS and Spitzer. The external planet (LHS 1140 b) is a rocky super-Earth that is located in the middle of the habitable zone of this low-mass star. All these properties place this system at the forefront of the habitable exoplanet exploration, and it therefore constitutes a relevant case for further astrobiological studies, including atmospheric observations. Aims. We further characterize this system by improving the physical and orbital properties of the known planets, search for additional planetary-mass components in the system, and explore the possibility of co-orbitals. Methods. We collected 113 new high-precision radial velocity observations with ESPRESSO over a 1.5-yr time span with an average photon-noise precision of 1.07 m s−1. We performed an extensive analysis of the HARPS and ESPRESSO datasets and also analyzed them together with the new TESS photometry. We analyzed the Bayesian evidence of several models with different numbers of planets and orbital configurations. Results. We significantly improve our knowledge of the properties of the known planets LHS 1140 b (Pb ~ 24.7 days) and LHS 1140 c (Pc ~ 3.77 days). We determine new masses with a precision of 6% for LHS 1140 b (6.48 ± 0.46 M⊕) and 9% for LHS 1140 c (mc = 1.78 ± 0.17 M⊕). This reduces the uncertainties relative to previously published values by half. Although both planets have Earth-like bulk compositions, the internal structure analysis suggests that LHS 1140 b might be iron-enriched and LHS 1140 c might be a true Earth twin. In both cases, the water content is compatible to a maximum fraction of 10–12% in mass, which is equivalent to a deep ocean layer of 779 ± 650 km for the habitable-zone planet LHS 1140 b. Our results also provide evidence for a new planet candidate in the system (md = 4.8 ± 1.1M⊕) on a 78.9-day orbital period, which is detected through three independent methods. The analysis also allows us to discard other planets above 0.5 M⊕ for periods shorter than 10 days and above 2 M⊕ for periods up to one year. Finally, our co-orbital analysis discards co-orbital planets in the tadpole and horseshoe configurations of LHS 1140 b down to 1 M⊕ with a 95% confidence level (twice better than with the previous HARPS dataset). Indications for a possible co-orbital signal in LHS 1140 c are detected in both radial velocity (alternatively explained by a high eccentricity) and photometric data (alternatively explained by systematics), however. Conclusions. The new precise measurements of the planet properties of the two transiting planets in LHS 1140 as well as the detection of the planet candidate LHS 1140 d make this system a key target for atmospheric studies of rocky worlds at different stellar irradiations.
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-2017-0737
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
Two neighbours of the ultra-short-period Earth-sized planet K2-157 b in the warm Neptunian savanna
(EDP Sciences, 2025-07-22) Castro-González, Amadeo; Bouchy, F.; Correia, A. C. M.; Sozzetti, A.; Lillo Box, J.; Figueira, P.; Lavie, B.; Lovis, C.; Hobson, Melissa J.; Sousa, S. G.; Adibekyan, Vardan; Standing, Matthew R.; Hara, Nathan C.; Barrado, David; Silva, André; Bourrier, V.; Korth, J.; Santos, Nuno C.; Damasso, M.; Zapatero Osorio, María Rosa; Rodrigues, José; Alibert, Yann; Barros, S. C. C.; Cristiani, S.; Marcantonio, Paolo Di; González Hernández, J. I.; Lo Curto, G.; Martins, C. J. A. P.; Nunes, Nelson J.; Pallé, E.; Pepe, Francesco; Suárez Mascareño, A.; Tabernero, H. M.; Fundacao para a Ciencia e a Tecnologia (FCT); European Commission (EC); Centros de Excelencia Severo Ochoa, INSTITUTO DE ASTROFÍSICA DE CANARIAS (IAC), SEV-2015-0548
[Context] The formation and evolution of ultra-short-period (USP) rocky planets is poorly understood. However, it is widely thought that these planets could not have formed at their present-day close-in orbits, but instead migrated inwards through interactions with outer neighbours. [Aims] We aim to confirm and characterise the USP Earth-sized validated planet K2-157 b (Porb = 8.8 h) and constrain the presence of additional companions in the system through radial velocity (RV) measurements. [Methods] We measured 49 RVs with the ESPRESSO spectrograph and tested different planetary and non-planetary configurations to infer the model that best represents our data set. We derived the orbital and physical properties of the system through a global RV and transit model. [Results] We detected two additional super-Neptune-mass planets located within the warm Neptunian savanna, K2-157 c (Porb,c = 25.942−0.044+0.045d, Mp,c sin i = 30.8 ± 1.9 M⊕) and K2-157 d (Porb,d = 66.50−0.59+0.71d, Mp,d sin i = 23.3 ± 2.5 M⊕). The joint analysis constrains the mass of K2-157 b at the 2.7σ level, Mp,b = 1.14−0.42+0.41 M⊕ (< 2.4 M⊕ at 3σ), which, together with the inferred radius, Rp,b = 0.935 ± 0.090 R⊕, make the planet compatible with a rocky composition with a likely (68% confidence) higher iron-to-silicate mass fraction than Earth. K2 data discard non-grazing transit configurations for K2-157 c (ic < 88.4° at 3σ), and ESPRESSO data constrain the eccentricities of K2-157 c and K2-157 d to ec < 0.2 and ed < 0.5 at 3σ. Our dynamical analysis indicates that the system is stable for eccentricities up to ec, ed ~ 0.3 and mutual inclinations up to ~60°. At a population level, we find that the trend that the closest USP planets tend to orbit late-type stars does not hold when scaling the orbital separation to the Roche limit, which suggests that the orbital distribution of the closest planets across spectral types is primarily determined by tidal disruption. [Conclusions] The orbital architecture of K2-157 is unusual in the known exoplanet plethora, with only one similar case reported to date: 55 Cnc. The USP planets of these systems, being accompanied by massive, long-period, relatively spaced, and possibly misaligned neighbours, could have migrated inwards through eccentricity-based mechanisms triggered by secular interactions.