TY - JOUR
T1 - HD 23472
T2 - a multi-planetary system with three super-Earths and two potential super-Mercuries
AU - Barros, S. C.C.
AU - Demangeon, O. D.S.
AU - Alibert, Y.
AU - Leleu, A.
AU - Adibekyan, V.
AU - Lovis, C.
AU - Bossini, D.
AU - Sousa, S. G.
AU - Hara, N.
AU - Bouchy, F.
AU - Lavie, B.
AU - Rodrigues, J.
AU - Gomes Da Silva, J.
AU - Lillo-Box, J.
AU - Pepe, F. A.
AU - Tabernero, H. M.
AU - Zapatero Osorio, M. R.
AU - Sozzetti, A.
AU - Suárez Mascareño, A.
AU - Micela, G.
AU - Allende Prieto, C.
AU - Cristiani, S.
AU - Damasso, M.
AU - Di Marcantonio, P.
AU - Ehrenreich, D.
AU - Faria, J.
AU - Figueira, P.
AU - González Hernández, J. I.
AU - Jenkins, J.
AU - Lo Curto, G.
AU - Martins, C. J.A.P.
AU - Micela, G.
AU - Nunes, N. J.
AU - Pallé, E.
AU - Santos, N. C.
AU - Rebolo, R.
AU - Seager, S.
AU - Twicken, J. D.
AU - Udry, S.
AU - Vanderspek, R.
AU - Winn, J. N.
N1 - Funding Information:
The authors acknowledge the ESPRESSO project team for its effort and dedication in building the ESPRESSO instrument. This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. This work has made use of data from the European Space Agency (ESA) mission (Gaia, https://www.cosmos.esa.int/web/gaia ), processed by the Gaia Data Processing and Analysis Consortium ( dpac, https ://www.cosmos.esa.int/web/gaia/dpac/consortium ). Funding for the dpac has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. This work was supported by FCT – Fundação para a Ciência – through national funds and by FEDER through COMPETE2020 – Programa Operacional Competitividade e Internacionalização by these grants: UID/FIS/04434/2019; UIDB/04434/2020; UIDP/04434/2020; PTDC/FIS-AST/32113/2017 & POCI-01-0145-FEDER-032113; PTDC/FIS-AST/28953/2017 & POCI-01-0145-FEDER-028953; PTDC/FIS-AST/28987/2017 & POCI-01-0145-FEDER-028987; PTDC/FISAST/30389/2017 & POCI-01-0145-FEDER-030389. CJ.A.P.M. acknowledges FCT and POCH/FSE (EC) support through Investigador FCT Contract 2021.01214.CEECIND/CP1658/CT0001. O.D.S.D. is supported in the form of work contract (DL 57/2016/CP1364/CT0004) funded by FCT. J.I.G.H., R.R., C.A.P. and A.S.M. acknowledge financial support from the Spanish Ministry of Science and Innovation (MICIN) project PID2020-117493GB-I00. A.S.M., J.I.G.H. and R.R. also acknowledge financial support from the Government of the Canary Islands project ProID2020010129. This work has been carried out with the support of the framework of the National Centre of Competence in Research PlanetS supported by the Swiss National Science Foundation (SNSF). The authors acknowledge the financial support of the SNSF and in particular Y.A. and J.H. acknowledge the SNSF for supporting research through the grant 200020_19203. A.S. acknowledges support from the Italian Space Agency (ASI) under contract 2018-24-HH.O. The financial contribution from the agreement ASI-INAF no. 2018-16-HH.O is gratefully acknowledged. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (project Four Aces ; grant agreement No 724427). It has also been carried out in the frame of the National Centre for Competence in Research PlanetS supported by the Swiss National Science Foundation (SNSF). D.E. acknowledges financial support from the Swiss National Science Foundation for project 200021_200726. FPE and CLO would like to acknowledge the Swiss National Science Foundation (SNSF) for supporting research with ESPRESSO through the SNSF grants no. 140649, 152721, 166227 and 184618. The ESPRESSO Instrument Project was partially funded through SNSF’s FLARE Programme for large infrastructures. J.L.-B. acknowledges financial support received from “la Caixa” Foundation (ID 100010434) and from the European Union’s Horizon 2020 research and innovation programme under the Marie Slodowska-Curie grant agreement no. 847648, with fellowship code LCF/BQ/PI20/11760023. This research has also been partly funded by the Spanish State Research Agency (AEI) Projects No. PID2019-107061GB-C61 and No. MDM-2017-0737 Unidad de Excelencia “María de Maeztu” – Centro de Astrobiología (INTA-CSIC). We acknowledge the use of public TESS data from pipelines at the TESS Science Office and at the TESS Science Processing Operations Center. Resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center for the production of the SPOC data products. We thank Lisa Kaltenegger for useful discussions.
Publisher Copyright:
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PY - 2022/9/1
Y1 - 2022/9/1
N2 - Context. Comparing the properties of planets orbiting the same host star, and thus formed from the same accretion disc, helps in constraining theories of exoplanet formation and evolution. As a result, the scientific interest in multi-planetary systems is growing with the increasing number of detections of planetary companions. Aims. We report the characterisation of a multi-planetary system composed of five exoplanets orbiting the K-dwarf HD 23472 (TOI-174). Methods. In addition to the two super-Earths that were previously confirmed, we confirm and characterise three Earth-size planets in the system using ESPRESSO radial velocity observations. The planets of this compact system have periods of Pd ∼ 3.98, Pe ∼ 7.90, Pf ∼ 12.16, Pb ∼ 17.67, and Pc ∼ 29.80 days and radii of Rd ∼ 0.75, Re ∼ 0.82, Rf ∼ 1.13, Rb ∼ 2.01, and, Rc ∼ 1.85 R· .Because of its small size, its proximity to planet d s transit, and close resonance with planet d, planet e was only recently found. Results. The planetary masses were estimated to be Md = 0.54 ± 0.22, Me = 0.76 ± 0.30, Mf = 0.64-0.39+0.46, Mb = 8.42-0.84+0.83, and Mc = 3.37-0.87+0.92 M· . These planets are among the lightest planets, with masses measured using the radial velocity method, demonstrating the very high precision of the ESPRESSO spectrograph. We estimated the composition of the system s five planets and found that their gas and water mass fractions increase with stellar distance, suggesting that the system was shaped by irradiation. The high density of the two inner planets (ρd = 7.5-3.1+3.9 and ρe = 7.5-3.0+3.9 g cm-3) indicates that they are likely to be super-Mercuries. This is supported by the modelling of the internal structures of the planets, which also suggests that the three outermost planets have significant water or gas content. Conclusions. If the existence of two super-Mercuries in the system is confirmed, this system will be the only one known to feature two super-Mercuries, making it an excellent testing bed for theories of super-Mercuries formation. Furthermore, the system is close to a Laplace resonance, and further monitoring could shed light on how it was formed. Its uniqueness and location in the continuous viewing zone of the James Webb space telescope will make it a cornerstone of future in-depth characterisations.
AB - Context. Comparing the properties of planets orbiting the same host star, and thus formed from the same accretion disc, helps in constraining theories of exoplanet formation and evolution. As a result, the scientific interest in multi-planetary systems is growing with the increasing number of detections of planetary companions. Aims. We report the characterisation of a multi-planetary system composed of five exoplanets orbiting the K-dwarf HD 23472 (TOI-174). Methods. In addition to the two super-Earths that were previously confirmed, we confirm and characterise three Earth-size planets in the system using ESPRESSO radial velocity observations. The planets of this compact system have periods of Pd ∼ 3.98, Pe ∼ 7.90, Pf ∼ 12.16, Pb ∼ 17.67, and Pc ∼ 29.80 days and radii of Rd ∼ 0.75, Re ∼ 0.82, Rf ∼ 1.13, Rb ∼ 2.01, and, Rc ∼ 1.85 R· .Because of its small size, its proximity to planet d s transit, and close resonance with planet d, planet e was only recently found. Results. The planetary masses were estimated to be Md = 0.54 ± 0.22, Me = 0.76 ± 0.30, Mf = 0.64-0.39+0.46, Mb = 8.42-0.84+0.83, and Mc = 3.37-0.87+0.92 M· . These planets are among the lightest planets, with masses measured using the radial velocity method, demonstrating the very high precision of the ESPRESSO spectrograph. We estimated the composition of the system s five planets and found that their gas and water mass fractions increase with stellar distance, suggesting that the system was shaped by irradiation. The high density of the two inner planets (ρd = 7.5-3.1+3.9 and ρe = 7.5-3.0+3.9 g cm-3) indicates that they are likely to be super-Mercuries. This is supported by the modelling of the internal structures of the planets, which also suggests that the three outermost planets have significant water or gas content. Conclusions. If the existence of two super-Mercuries in the system is confirmed, this system will be the only one known to feature two super-Mercuries, making it an excellent testing bed for theories of super-Mercuries formation. Furthermore, the system is close to a Laplace resonance, and further monitoring could shed light on how it was formed. Its uniqueness and location in the continuous viewing zone of the James Webb space telescope will make it a cornerstone of future in-depth characterisations.
KW - Planets and satellites: composition
KW - Planets and satellites: detection
KW - Planets and satellites: terrestrial planets
KW - Stars: individual: HD 23472
KW - Techniques: photometric
KW - Techniques: radial velocities
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U2 - 10.1051/0004-6361/202244293
DO - 10.1051/0004-6361/202244293
M3 - Article
AN - SCOPUS:85139721354
SN - 0004-6361
VL - 665
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A154
ER -