Examinando por Autor "Mousis, O."

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A remnant planetary core in the hot-Neptune desert
(Springer Nature Research Journals, 2020-07-01) Armstrong, D. J.; López, T. A.; Adibekyan, V.; Booth, R. A.; Bryant, E. M.; Collins, K. A.; Deleuil, M.; Emsenhuber, A.; Huang, C. X.; King, G. W.; Lillo Box, J.; Lissauer, J. J.; Matthews, E.; Mousis, O.; Nielsen, L. D.; Osborn, Hugh P.; Otegi, J.; Santos, N. C.; Sousa, S. G.; Stassun, K. G.; Veras, D.; Ziegler, C.; Acton, J. S.; Almenara, J. M.; Anderson, D. R.; Barrado, D.; Barros, S. C. C.; Bayliss, D.; Belardi, C.; Bouchy, F.; Briceño, C.; Brogi, M.; Brown, D. J. A.; Burleigh, M. R.; Casewell, S. L.; Chausev, A.; Ciardi, D. R.; Collins, K. I.; Colón, K. D.; Cooke, B. F.; Crossfield, J. M.; Díaz, R. F.; Delgado Mena, E.; Gandhi, O. D. S.; Gill, Samuel; Gonzales, E. J.; Goad, M. R.; Günther, M. N.; Helled, R.; Hojjatpanah, S.; Howell, Steve B.; Jackman, J.; Jenkins, J. S.; Jenkins, J. M.; Jensen, E. L. N.; Kennedy, G. M.; Latham, D. W.; Law, N.; Osborn, M.; Pollacco, D.; Queloz, D.; Raynard, L.; Ricker, G. R.; Rowden, P.; Santerne, A.; Schlieder, J. E.; Seager, S.; Sha, L.; Tan, T. G.; Tilbrook, R. H.; Ting, E.; Udry, S.; Vanderspek, R.; Watson, C. A.; West, R. G.; Wilson, P. A.; Winn, J. N.; Wheatley, P.; Villaseñor, J. N.; Vines, J. I.; Zhan, Z.; National Aeronautics and Space Administration (NASA); Fundação para a Ciência e a Tecnologia (FCT); Agencia Estatal de Investigación (AEI); Science and Technology Facilities Council (STFC); Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT); Collins, K. A. [0000-0002-4317-142X]; Lillo Box, J. [0000-0003-3742-1987]; Matthews, E. [0000-0003-0593-1560]; Sousa, S. [0000-0002-3631-6440]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
The interiors of giant planets remain poorly understood. Even for the planets in the Solar System, difficulties in observation lead to large uncertainties in the properties of planetary cores. Exoplanets that have undergone rare evolutionary processes provide a route to understanding planetary interiors. Planets found in and near the typically barren hot-Neptune 'desert'(1,2)(a region in mass-radius space that contains few planets) have proved to be particularly valuable in this regard. These planets include HD149026b(3), which is thought to have an unusually massive core, and recent discoveries such as LTT9779b(4)and NGTS-4b(5), on which photoevaporation has removed a substantial part of their outer atmospheres. Here we report observations of the planet TOI-849b, which has a radius smaller than Neptune's but an anomalously large mass of39.1-2.6+2.7Earth masses and a density of5.2-0.8+0.7grams per cubic centimetre, similar to Earth's. Interior-structure models suggest that any gaseous envelope of pure hydrogen and helium consists of no more than3.9-0.9+0.8 per cent of the total planetary mass. The planet could have been a gas giant before undergoing extreme mass loss via thermal self-disruption or giant planet collisions, or it could have avoided substantial gas accretion, perhaps through gap opening or late formation(6). Although photoevaporation rates cannot account for the mass loss required to reduce a Jupiter-like gas giant, they can remove a small (a few Earth masses) hydrogen and helium envelope on timescales of several billion years, implying that any remaining atmosphere on TOI-849b is likely to be enriched by water or other volatiles from the planetary interior. We conclude that TOI-849b is the remnant core of a giant planet.
Acceso Abierto
Mass determinations of the three mini-Neptunes transiting TOI-125
(Oxford Academics: Oxford University Press, 2020-01-23) Nielsen, L. D.; Gandolfi, D.; Armstrong, D. J.; Jenkins, J. S.; Fridlund, M.; Santos, N. C.; Dai, F.; Adibekyan, V.; Luque, R.; Steffen, J. H.; Esposito, M.; Meru, F.; Sabotta, S.; Bolmont, É.; Kossakowski, D.; Otegi, J. F.; Murgas Alcaino, F.; Stalport, M.; Rodler, F.; Díaz, M. R.; Kurtovic, N. T.; Ricker, G.; Vanderspek, R.; Latham, D. W.; Seager, S.; Winn, J. N.; Jenkins, J. M.; Allart, R.; Almenara, J. M.; Barrado, D.; Barros, S. C. C.; Bayliss, D.; Berdiñas, Z. M.; Boisse, I.; Bouchy, F.; Boyd, P.; Brown, D. J. A.; Bryant, E. M.; Burke, C. J.; Cochran, W. D.; Cooke, B. F.; Demangeon, O. D. S.; Díaz, R. F.; Dittman, J.; Dorn, C.; Dumusque, X.; García, R. A.; González Cuesta, L.; Georgieva, I.; Guerrero, N.; Hatzes, A. P.; Helled, R.; Henze, C. E.; Hojjatpanah, S.; Korth, J.; Lam, K. W. F.; Lillo Box, J.; López, T. A.; Livingston, J.; Mathur, S.; Mousis, O.; Narita, N.; Osborn, Hugh P.; Pallé, E.; Peña Rojas, P. A.; Persson, C. M.; Quinn, S. N.; Rauer, H.; Redfield, S.; Santerne, A.; Dos Santos, L. A.; Seidel, J. V.; Sousa, S. G.; Ting, E. B.; Turbet, M.; Udry, S.; Vanderburg, A.; Van Eylen, V.; Vines, J. I.; Wheatley, P. J.; Wilson, P. A.; Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT); Swiss National Science Foundation (SNSF); Deutsche Forschungsgemeinschaft (DFG); Agencia Estatal de Investigación (AEI); European Southern Observatory (ESO); Swiss National Centre of Competence inResearch (NCCR); National Aeronautics and Space Administration (NASA); Fundacao para a Ciencia e a Tecnologia (FCT); European Research Council (ERC); Vanderburg, A. [0000-0001-7246-5438]; Dos Santos, L. [0000-0002-2248-3838]; Barrado, D. [0000-0002-5971-9242]; Cochran, W. [0000-0001-9662-3496]; Lillo Box, J. [0000-0003-3742-1987]; Barros, S. [0000-0003-2434-3625]; Stalport, M. [0000-0003-0996-6402]; Dorn, C. [0000-0001-6110-4610]; Nielsen, L. D. [0000-0002-5254-2499]; Seidel, J. V. [0000-0002-7990-9596]; Diaz, M. R. [0000-0002-2100-3257]; Bolmont, E. [0000-0001-5657-4503]; Adibekyan, V. [0000-0002-0601-6199]; Van Eylen, V. [0000-0001-5542-8870]; Armstrong, D. [0000-0002-5080-4117]; Korth, J. [0000-0002-0076-6239]; Díaz, R. [0000-0001-9289-5160]; Santos, N. [0000-0003-4422-2919]; Luque, R. [0000-0002-4671-2957]; Turbet, M. [0000-0003-2260-9856]; Mathur, S. [0000-0002-0129-0316]; Strom, P. A. [0000-0002-7823-1090]; Sabotta, S. [0000-0001-9078-5574]; Wheatley, P. [0000-0003-1452-2240]; Hojjatpanah, S. [0000-0002-0417-1902]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
The Transiting Exoplanet Survey Satellite, TESS, is currently carrying out an all-sky search for small planets transiting bright stars. In the first year of the TESS survey, a steady progress was made in achieving the mission's primary science goal of establishing bulk densities for 50 planets smaller than Neptune. During that year, the TESS's observations were focused on the southern ecliptic hemisphere, resulting in the discovery of three mini-Neptunes orbiting the star T01-125, a V = 11,0 KO dwarf. We present intensive HARPS radial velocity observations, yielding precise mass measurements for TO1-125b, TOI-125c, and TOI-125d. TOI-125b has an orbital period of 4,65 d, a radius of 2,726 + 0,075 RE, a mass of 9,50 0,88 ME, and is near the 2:1 mean motion resonance with TOI-125c at 9.15 d. TOI-125c has a similar radius of 2,759 0.10 RE and a mass of 6,63 + 0,99 ME, being the puffiest of the three planets. T01-125d has an orbital period of 19,98 d and a radius of 2.93 + 0,17 RE and mass 13,6 1,2 ME, For T01-125b and d, we find unusual high eccentricities of 0.19 0.04 and 0.17+(c):(!,(, respectively. Our analysis also provides upper mass limits for the two low-SNR planet candidates in the system; for T01-125.04 (Rp = 1.36 RE, P = 0.53 d), we find a 2a upper mass limit of 1.6 ME, whereas T01-125.05 (RP = 4.2-'2E44 RE, P = 13.28 d) is unlikely a viable planet candidate with an upper mass limit of 2.7 ME. We discuss the internal structure of the three confirmed planets, as well as dynamical stability and system architecture for this intriguing exoplanet system.
Acceso Abierto
Masses for the seven planets in K2-32 and K2-233 Four diverse planets in resonant chain and the first young rocky worlds
(EDP Sciences, 2020-08-11) Lillo Box, J.; López, T. A.; Santerne, A.; Nielsen, L. D.; Barros, S. C. C.; Deleuil, M.; Acuña, L.; Mousis, O.; Sousa, S. G.; Adibekyan, V.; Armstrong, D. J.; Barrado, D.; Bayliss, D.; Brown, D. J. A.; Demangeon, O. D. S.; Dumusque, X.; Figueira, P.; Hojjatpanah, S.; Osborn, Hugh P.; Santos, N. C.; Udry, S.; Science and Technology Facilities Council (STFC); Agencia Estatal de Investigación (AEI); Fundacao para a Ciencia e a Tecnologia (FCT); Lillo Box, J. [0000-0003-3742-1987]; López, T. [0000-0001-6622-1250]; Santerne, A. [0000-0002-3586-1316]; Barros, S. [0000-0003-2434-3625]; Deleuil, M. [0000-0001-6036-0225]; Sousa, S. G. [0000-0001-9047-2965]; Adibekyan, V. [0000-0002-0601-6199]; Armstrong, D. J. [0000-0002-5080-4117]; Barrado, D. [0000-0002-5971-9242]; Bayliss, D. [0000-0001-6023-1335]; Brown, D. J. A. [0000-0003-1098-2442]; Demangeon, O. D. S. [0000-0001-7918-0355]; Dumusque, X. [0000-0002-9332-2011]; Figueira, P. [0000-0001-8504-283X]; Hojjatpanah, S. [0000-0002-0417-1902]; Osborn, H. [0000-0002-4047-4724]; Santos, N. C. [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. High-precision planetary densities are key pieces of information necessary to derive robust atmospheric properties for extrasolar planets. Measuring precise masses is the most challenging part of this task, especially in multi-planetary systems. The ESO-K2 collaboration focuses on the follow-up of a selection of multi-planetary systems detected by the K2 mission using the HARPS instrument with this goal in mind. Aims. In this work, we measure the masses and densities of two multi-planetary systems: a four-planet near resonant chain system (K2-32) and a young (~400 Myr old) planetary system consisting of three close-in small planets (K2-233). Methods. We obtained 199 new HARPS observations for K2-32 and 124 for K2-233 covering a long baseline of more than three years. We performed a joint analysis of the radial velocities and K2 photometry with PASTIS to precisely measure and constrained the properties of these planets, focusing on their masses and orbital properties. Results. We find that K2-32 is a compact scaled-down version of the Solar System’s architecture, with a small rocky inner planet (Me = 2.1−1.1+1.3 M⊕, Pe ~ 4.35 days) followed by an inflated Neptune-mass planet (Mb = 15.0−1.7+1.8 M⊕, Pb ~ 8.99 days) and two external sub-Neptunes (Mc = 8.1 ± 2.4 M⊕, Pc ~ 20.66 days; Md = 6.7 ± 2.5 M⊕, Pd ~ 31.72 days). K2-32 becomes one of the few multi-planetary systems with four or more planets known where all have measured masses and radii. Additionally, we constrain the masses of the three planets in the K2-233 system through marginal detection of their induced radial velocity variations. For the two inner Earth-size planets we constrain their masses at a 95% confidence level to be smaller than Mb < 11.3 M⊕ (Pb ~ 2.47 days), Mc < 12.8 M⊕ (Pc ~ 7.06 days). The outer planet is a sub-Neptune size planet with an inferred mass of Md = 8.3−4.7+5.2 M⊕ (Md < 21.1 M⊕, Pd ~ 24.36 days). Conclusions. Our observations of these two planetary systems confirm for the first time the rocky nature of two planets orbiting a young star, with relatively short orbital periods (<7 days). They provide key information for planet formation and evolution models of telluric planets. Additionally, the Neptune-like derived masses of the three planets, K2-32 b, c, d, puts them in a relatively unexplored regime of incident flux and planet mass, which is key for transmission spectroscopy studies in the near future.
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, N. C.; Correia, A. C. M.; Robutel, P.; Deleuil, M.; Barrado, D.; Sousa, S. G.; Bonfils, X.; Mousis, O.; Almenara, J. M.; Astudillo Defru, N.; Marcq, E.; Udry, S.; Lovis, C.; Pepe, F.; 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.