Examinando por Autor "Osborn, Hugh P."

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Acceso Abierto
A hot mini-Neptune in the radius valley orbiting solar analogue HD 110113
(Oxford Academics: Oxford University Press, 2021-01-25) Osborn, Hugh P.; Armstrong, D. J.; Adibekyan, V.; Collins, K. A.; Delgado Mena, E.; Howell, Steve B.; Hellier, C.; King, G. W.; Lillo Box, J.; Nielsen, L. D.; Otegi, J. F.; Santos, N. C.; Ziegler, C.; Anderson, D. R.; Briceño, C.; Burke, C. J.; Bayliss, D.; Barrado, D.; Bryant, E. M.; Brown, D. J. A.; Barros, S. C. C.; Bouchy, F.; Caldwell, D. A.; Conti, D.; Díaz, R. F.; Dragomir, D.; Deleuil, M.; Demanegon, O. D. S.; Dorn, C.; Daylan, T.; Figueira, P.; Helled, R.; Hoyer, S.; Jenkins, J. S.; Jensen, E. L. N.; Latham, D. W.; Law, N.; Louie, D.; Mann, A. W.; Osborn, A.; Pollacco, D.; Rodríguez, D. R.; Rackham, B. V.; Ricker, G.; Scott, N. J.; Sousa, S. G.; Seager, S.; Stassun, K. G.; Smith, J. C.; Strom, P.; Udry, S.; Villaseñor, J. N.; Vanderspek, R.; West, R.; Wheatley, P. J.; Winn, J. N.; Fundacao para a Ciencia e a Tecnologia (FCT); Science and Technology Facilities Council (STFC); Agencia Estatal de Investigación (AEI); National Aeronautics and Space Administration (NASA); UK Space Agency; Dorn, C. [0000-0001-6110-4610]; Anderson, D. [0000-0001-7416-7522]; Barros, S. [0000-0003-2434-3625]; Adibekyan, V. [0000-0002-0601-6199]; Armstrong, D. [0000-0002-5080-4117]; 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 report the discovery of HD 110113 b (TESS object of interest-755.01), a transiting mini-Neptune exoplanet on a 2.5-d orbit around the solar-analogue HD 110113 (Teff = 5730 K). Using TESS photometry and High Accuracy Radial velocity Planet Searcher (HARPS) radial velocities gathered by the NCORES program, we find that HD 110113 b has a radius of 2.05 ± 0.12 R⊕ and a mass of 4.55 ± 0.62 M⊕. The resulting density of 2.90+0.75−0.59 g cm−3 is significantly lower than would be expected from a pure-rock world; therefore HD 110113 b must be a mini-Neptune with a significant volatile atmosphere. The high incident flux places it within the so-called radius valley; however, HD 110113 b was able to hold on to a substantial (0.1–1 per cent) H–He atmosphere over its ∼4 Gyr lifetime. Through a novel simultaneous Gaussian process fit to multiple activity indicators, we were also able to fit for the strong stellar rotation signal with period 20.8 ± 1.2 d from the RVs and confirm an additional non-transiting planet, HD 110113 c, which has a mass of 10.5 ± 1.2 M⊕ and a period of 6.744+0.008−0.009 d.
Acceso Abierto
CHEOPS observations of the HD 108236 planetary system: a fifth planet, improved ephemerides, and planetary radii
(EDP Sciences, 2021-02-19) Bonfanti, A.; Delrez, L.; Hooton, M. J.; Wilson, T. G.; Fossati, L.; Alibert, Y.; Hoyer, S.; Mustill, A. J.; Osborn, H. P.; Adibekyan, V.; Gandolfi, D.; Van Eylen, V.; Viotto, V.; Walter, I.; Walton, N. A.; Wildi, F.; Wolter, D.; Salmon, S.; Sousa, S. G.; Tuson, A.; Van Grootel, V.; Cabrera, J.; Nascimbeni, V.; Maxted, P. F. L.; Barros, S. C. C.; Billot, N.; Bonfils, X.; Borsato, L.; Broeg, C.; Davies, M. B.; Deleuil, M.; Demangeon, O. D. S.; Fridlund, M.; Lacedelli, G.; Lendl, M.; Persson, C.; Santos, N. C.; Scandariato, G.; Szabó, Gy. M.; Collier Cameron, A.; Udry, S.; Benz, W.; Beck, M.; Ehrenreich, D.; Fortier, A.; Isaak, K. G.; Queloz, D.; Alonso, R.; Asquier, J.; Bandy, T.; Bárczy, T.; Barrado, D.; Barragán, O.; Baumjohann, W.; Beck, T.; Bekkelien, A.; Bergomi, M.; Brandeker, A.; Busch, M. D.; Cessa, V.; Charnoz, S.; Chazelas, B.; Van Damme, C. C.; Demory, B. O.; Erikson, A.; Farinato, J.; Futyan, D.; García Muñoz, Antonio; Gillon, M.; Guedel, M.; Guterman, P.; Hasiba, J.; Heng, K.; Hernández, E.; Kiss, L.; Kuntzer, T.; Laskar, J.; Lecavelier des Etangs, A.; Lovis, C.; Magrin, D.; Malvasio, L.; Marafatto, L.; Michaelis, H.; Munari, M.; Olofsson, G.; Ottacher, H.; Ottensamer, R.; Pagano, I.; Pallé, E.; Peter, G.; Piazza, D.; Piotto, G.; Pollacco, D.; Ragazzoni, R.; Rando, N.; Ratti, F.; Rauer, H.; Ribas, I.; Rieder, M.; Rohlfs, R.; Safa, F.; Salatti, M.; Ségransan, D.; Simon, A. E.; Smith, A. M. S.; Sordet, Michael; Steller, M.; Thomas, N.; Tschentscher, M.; Swiss Space Office (SSO); La Silla Observatory; Austrian Research Promotion Agency (FFG); European Research Council (ERC); Swiss National Science Foundation (SNSF); Agencia Estatal de Investigación (AEI); Generalitat de Catalunya; European Space Agency (ESA); Fundacao para a Ciencia e a Tecnologia (FCT); Belgian Federal Science Policy Office (BELSPO); Hungarian National Research, Development and Innovation Office (NKFIH); Istituto Nazionale di Astrofisica (INAF); Swedish National Infrastructure for Computing (SNIC); Bonfanti, A. [0000-0002-1916-5935]; Cameron, A. [0000-0002-8863-7828]; Santos, N. [0000-0003-4422-2919]; Mustill, A. J. [0000-0002-2086-3642]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Context. The detection of a super-Earth and three mini-Neptunes transiting the bright (V = 9.2 mag) star HD 108236 (also known as TOI-1233) was recently reported on the basis of TESS and ground-based light curves. Aims. We perform a first characterisation of the HD 108236 planetary system through high-precision CHEOPS photometry and improve the transit ephemerides and system parameters. Methods. We characterise the host star through spectroscopic analysis and derive the radius with the infrared flux method. We constrain the stellar mass and age by combining the results obtained from two sets of stellar evolutionary tracks. We analyse the available TESS light curves and one CHEOPS transit light curve for each known planet in the system. Results. We find that HD 108236 is a Sun-like star with R⋆ = 0.877 ± 0.008 R⊙, M⋆ = 0.869−0.048+0.050 M⊙, and an age of 6.7−5.1+4.0 Gyr. We report the serendipitous detection of an additional planet, HD 108236 f, in one of the CHEOPS light curves. For this planet, the combined analysis of the TESS and CHEOPS light curves leads to a tentative orbital period of about 29.5 days. From the light curve analysis, we obtain radii of 1.615 ± 0.051, 2.071 ± 0.052, 2.539−0.065+0.062, 3.083 ± 0.052, and 2.017−0.057+0.052 R⊕ for planets HD 108236 b to HD 108236 f, respectively. These values are in agreement with previous TESS-based estimates, but with an improved precision of about a factor of two. We perform a stability analysis of the system, concluding that the planetary orbits most likely have eccentricities smaller than 0.1. We also employ a planetary atmospheric evolution framework to constrain the masses of the five planets, concluding that HD 108236 b and HD 108236 c should have an Earth-like density, while the outer planets should host a low mean molecular weight envelope. Conclusions. The detection of the fifth planet makes HD 108236 the third system brighter than V = 10 mag to host more than four transiting planets. The longer time span enables us to significantly improve the orbital ephemerides such that the uncertainty on the transit times will be of the order of minutes for the years to come. A comparison of the results obtained from the TESS and CHEOPS light curves indicates that for a V ~ 9 mag solar-like star and a transit signal of ~500 ppm, one CHEOPS transit light curve ensures the same level of photometric precision as eight TESS transits combined, although this conclusion depends on the length and position of the gaps in the light curve.
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.