A joint effort to discover and characterize two resonant mini-Neptunes around TOI-1803 with TESS, HARPS-N, and CHEOPS

T. Zingales; L. Malavolta; L. Borsato; D. Turrini; A. Bonfanti; D. Polychroni; G. Mantovan; D. Nardiello; V. Nascimbeni; A. F. Lanza; A. Bekkelien; A. Sozzetti; C. Broeg; L. Naponiello; M. Lendl; A. S. Bonomo; A. E. Simon; S. Desidera; G. Piotto; L. Mancini; M. J. Hooton; A. Bignamini; J. A. Egger; A. Maggio; Y. Alibert; D. Locci; L. Delrez; F. Biassoni; L. Fossati; L. Cabona; G. Lacedelli; I. Carleo; P. Leonardi; G. Andreuzzi; A. Brandeker; R. Cosentino; A. C. M. Correia; R. Claudi; R. Alonso; M. Damasso; T. G. Wilson; T. Bàrczy; M. Pinamonti; D. Baker; K. Barkaoui; D. Barrado Navascues; S. C. C. Barros; W. Baumjohann; T. Beck; C. Beichman; W. Benz; A. Bieryla; N. Billot; P. Bosch-Cabot; L. G. Bouma; D. R. Ciardi; A. Collier Cameron; K. A. Collins; Ian J. M. Crossfield; Sz Csizmadia; P. E. Cubillos; M. B. Davies; M. Deleuil; A. Deline; O. D. S. Demangeon; B. -O. Demory; A. Derekas; D. Dragomir; B. Edwards; D. Ehrenreich; A. Erikson; B. Falk; A. Fortier; M. Fridlund; A. Fukui; D. Gandolfi; K. Gazeas; M. Gillon; E. Gonzales; M. Gudel; P. Guerra; M. N. Günther; A. Heitzmann; Ch Helling; S. B. Howell; K. G. Isaak; J. Jenkins; L. L. Kiss; J. Korth; K. W. F. Lam; J. Laskar; A. Lecavelier des Etangs; D. Magrin; R. Matson; E. C. Matthews; P. F. L. Maxted; S. McDermott; M. Munari; C. Mordasini; N. Narita; G. Olofsson; R. Ottensamer; I. Pagano; E. Pallè; G. Peter; D. Pollacco; D. Queloz; R. Ragazzoni; N. Rando; F. Ratti; H. Rauer; I. Ribas; S. Salmon; N. C. Santos; G. Scandariato; S. Seager; D. Sègransan; A. M. S. Smith; J. Schlieder; R. P. Schwarz; A. Shporer; S. G. Sousa; M. Stalport; M. Steinberger; S. Sulis; Gy M. Szabò; J. D. Twicken; S. Udry; V. Van Grootel; J. Venturini; E. Villaver; N. A. Walton; J. N. Winn

doi:10.1051/0004-6361/202451180

A joint effort to discover and characterize two resonant mini-Neptunes around TOI-1803 with TESS, HARPS-N, and CHEOPS

T. Zingales^*, L. Malavolta, L. Borsato, D. Turrini, A. Bonfanti, D. Polychroni, G. Mantovan, D. Nardiello, V. Nascimbeni, A. F. Lanza, A. Bekkelien, A. Sozzetti, C. Broeg, L. Naponiello, M. Lendl, A. S. Bonomo, A. E. Simon, S. Desidera, G. Piotto, L. ManciniM. J. Hooton, A. Bignamini, J. A. Egger, A. Maggio, Y. Alibert, D. Locci, L. Delrez, F. Biassoni, L. Fossati, L. Cabona, G. Lacedelli, I. Carleo, P. Leonardi, G. Andreuzzi, A. Brandeker, R. Cosentino, A. C. M. Correia, R. Claudi, R. Alonso, M. Damasso, T. G. Wilson, T. Bàrczy, M. Pinamonti, D. Baker, K. Barkaoui, D. Barrado Navascues, S. C. C. Barros, W. Baumjohann, T. Beck, C. Beichman, W. Benz, A. Bieryla, N. Billot, P. Bosch-Cabot, L. G. Bouma, D. R. Ciardi, A. Collier Cameron, K. A. Collins, Ian J. M. Crossfield, Sz Csizmadia, P. E. Cubillos, M. B. Davies, M. Deleuil, A. Deline, O. D. S. Demangeon, B. -O. Demory, A. Derekas, D. Dragomir, B. Edwards, D. Ehrenreich, A. Erikson, B. Falk, A. Fortier, M. Fridlund, A. Fukui, D. Gandolfi, K. Gazeas, M. Gillon, E. Gonzales, M. Gudel, P. Guerra, M. N. Günther, A. Heitzmann, Ch Helling, S. B. Howell, K. G. Isaak, J. Jenkins, L. L. Kiss, J. Korth, K. W. F. Lam, J. Laskar, A. Lecavelier des Etangs, D. Magrin, R. Matson, E. C. Matthews, P. F. L. Maxted, S. McDermott, M. Munari, C. Mordasini, N. Narita, G. Olofsson, R. Ottensamer, I. Pagano, E. Pallè, G. Peter, D. Pollacco, D. Queloz, R. Ragazzoni, N. Rando, F. Ratti, H. Rauer, I. Ribas, S. Salmon, N. C. Santos, G. Scandariato, S. Seager, D. Sègransan, A. M. S. Smith, J. Schlieder, R. P. Schwarz, A. Shporer, S. G. Sousa, M. Stalport, M. Steinberger, S. Sulis, Gy M. Szabò, J. D. Twicken, S. Udry, V. Van Grootel, J. Venturini, E. Villaver, N. A. Walton, J. N. Winn

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

Abstract

Context. The discovery and characterization of mini-Neptunes hold a potentially crucial impact on planetary formation and evolution theories. Estimating their orbital parameters and atmospheric properties would provide valuable hints to improve formation and atmospheric models.

Aims. We present the discovery of two mini-Neptunes near a 2:1 orbital resonance configuration orbiting the K0 star TOI-1803. We describe in detail their orbital architecture and suggest some possible formation and evolution scenarios.

Methods. Using CHEOPS, TESS, and HARPS-N datasets, we estimated the radius and the mass of both planets. We used a multidimensional Gaussian process with a quasi-periodic kernel to disentangle the planetary components from the stellar activity in the HARPS-N dataset. We performed dynamical modeling to explain the orbital configuration and performed planetary formation and evolution simulations. For the least dense planet, we assumed different atmospheric compositions and defined possible atmospheric scenarios with simulated JWST observations.

Results. TOI-1803 b and TOI-1803 c have orbital periods of ∼6.3 and ∼12.9 days, respectively, residing in close proximity to a 2:1 orbital resonance. Ground-based photometric follow-up observations have revealed significant transit timing variations (TTV) with an amplitude of ∼10 min and ∼40 min, respectively, for planets b and -c. With the masses computed from the radial velocities dataset, we obtained a density of (0.39 ± 0.10) ρ_⊕ and (0.076 ± 0.038) ρ_⊕ for planets b and -c, respectively. TOI-1803 c is among the least dense mini-Neptunes currently known, and due to its inflated atmosphere, it is a suitable target for transmission spectroscopy with JWST. With NIRSpec observations, we could understand whether the planet has kept its primary atmosphere or not, which would constrain our formation models.

Conclusions. We report the discovery of two mini-Neptunes close to a 2:1 orbital resonance. The detection of significant TTVs from ground-based photometry opens scenarios for a more precise mass determination. TOI-1803 c is one of the least dense mini-Neptunes known so far, and it is of great interest among the scientific community since it could constrain current formation scenarios. JWST observations could give us valuable insights to characterize this interesting system.

Original language	English
Article number	A273
Number of pages	26
Journal	Astronomy & Astrophysics
Volume	695
DOIs	https://doi.org/10.1051/0004-6361/202451180
Publication status	Published - 31 Mar 2025

Keywords

Planets and satellites: detection
Planets and satellites: dynamical evolution and stability
Planets and satellites: formation
Planets and satellites: fundamental parameters
Planets and satellites: interiors

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Zingales_2025_AaA_Joint-effort-discover-two-mini-Neptunes-TOI-1803_CC
© The Authors 2025. Open Access article, published under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Final published version, 21.9 MBLicence: CC BY

AO2 - Professor Andrew Cameron: Project AO2 - Andrew Cameron
Cameron, A. (PI)
Science & Technology Facilities Council
1/04/21 → 31/03/24
Project: Standard
H2020 MSCA ITN EJD 2019: H2020 MSCA ITN EJD 2019 CHAMELEON
Helling, C. (PI)
European Commission Joint Research Centre
1/06/20 → 31/05/24
Project: Standard

Cite this

Zingales, T., Malavolta, L., Borsato, L., Turrini, D., Bonfanti, A., Polychroni, D., Mantovan, G., Nardiello, D., Nascimbeni, V., Lanza, A. F., Bekkelien, A., Sozzetti, A., Broeg, C., Naponiello, L., Lendl, M., Bonomo, A. S., Simon, A. E., Desidera, S., Piotto, G., ... Winn, J. N. (2025). A joint effort to discover and characterize two resonant mini-Neptunes around TOI-1803 with TESS, HARPS-N, and CHEOPS. Astronomy & Astrophysics, 695, Article A273. https://doi.org/10.1051/0004-6361/202451180

@article{c888ea3c1cd94d938d48e9dea4267548,

title = "A joint effort to discover and characterize two resonant mini-Neptunes around TOI-1803 with TESS, HARPS-N, and CHEOPS",

abstract = "Context. The discovery and characterization of mini-Neptunes hold a potentially crucial impact on planetary formation and evolution theories. Estimating their orbital parameters and atmospheric properties would provide valuable hints to improve formation and atmospheric models.Aims. We present the discovery of two mini-Neptunes near a 2:1 orbital resonance configuration orbiting the K0 star TOI-1803. We describe in detail their orbital architecture and suggest some possible formation and evolution scenarios.Methods. Using CHEOPS, TESS, and HARPS-N datasets, we estimated the radius and the mass of both planets. We used a multidimensional Gaussian process with a quasi-periodic kernel to disentangle the planetary components from the stellar activity in the HARPS-N dataset. We performed dynamical modeling to explain the orbital configuration and performed planetary formation and evolution simulations. For the least dense planet, we assumed different atmospheric compositions and defined possible atmospheric scenarios with simulated JWST observations.Results. TOI-1803 b and TOI-1803 c have orbital periods of ∼6.3 and ∼12.9 days, respectively, residing in close proximity to a 2:1 orbital resonance. Ground-based photometric follow-up observations have revealed significant transit timing variations (TTV) with an amplitude of ∼10 min and ∼40 min, respectively, for planets b and -c. With the masses computed from the radial velocities dataset, we obtained a density of (0.39 ± 0.10) ρ⊕ and (0.076 ± 0.038) ρ⊕ for planets b and -c, respectively. TOI-1803 c is among the least dense mini-Neptunes currently known, and due to its inflated atmosphere, it is a suitable target for transmission spectroscopy with JWST. With NIRSpec observations, we could understand whether the planet has kept its primary atmosphere or not, which would constrain our formation models.Conclusions. We report the discovery of two mini-Neptunes close to a 2:1 orbital resonance. The detection of significant TTVs from ground-based photometry opens scenarios for a more precise mass determination. TOI-1803 c is one of the least dense mini-Neptunes known so far, and it is of great interest among the scientific community since it could constrain current formation scenarios. JWST observations could give us valuable insights to characterize this interesting system.",

keywords = "Planets and satellites: detection, Planets and satellites: dynamical evolution and stability, Planets and satellites: formation, Planets and satellites: fundamental parameters, Planets and satellites: interiors",

author = "T. Zingales and L. Malavolta and L. Borsato and D. Turrini and A. Bonfanti and D. Polychroni and G. Mantovan and D. Nardiello and V. Nascimbeni and Lanza, {A. F.} and A. Bekkelien and A. Sozzetti and C. Broeg and L. Naponiello and M. Lendl and Bonomo, {A. S.} and Simon, {A. E.} and S. Desidera and G. Piotto and L. Mancini and Hooton, {M. J.} and A. Bignamini and Egger, {J. A.} and A. Maggio and Y. Alibert and D. Locci and L. Delrez and F. Biassoni and L. Fossati and L. Cabona and G. Lacedelli and I. Carleo and P. Leonardi and G. Andreuzzi and A. Brandeker and R. Cosentino and Correia, {A. C. M.} and R. Claudi and R. Alonso and M. Damasso and Wilson, {T. G.} and T. B{\`a}rczy and M. Pinamonti and D. Baker and K. Barkaoui and {Barrado Navascues}, D. and Barros, {S. C. C.} and W. Baumjohann and T. Beck and C. Beichman and W. Benz and A. Bieryla and N. Billot and P. Bosch-Cabot and Bouma, {L. G.} and Ciardi, {D. R.} and Cameron, {A. Collier} and Collins, {K. A.} and Crossfield, {Ian J. M.} and Sz Csizmadia and Cubillos, {P. E.} and Davies, {M. B.} and M. Deleuil and A. Deline and Demangeon, {O. D. S.} and Demory, {B. -O.} and A. Derekas and D. Dragomir and B. Edwards and D. Ehrenreich and A. Erikson and B. Falk and A. Fortier and M. Fridlund and A. Fukui and D. Gandolfi and K. Gazeas and M. Gillon and E. Gonzales and M. Gudel and P. Guerra and G{\"u}nther, {M. N.} and A. Heitzmann and Ch Helling and Howell, {S. B.} and Isaak, {K. G.} and J. Jenkins and Kiss, {L. L.} and J. Korth and Lam, {K. W. F.} and J. Laskar and {Lecavelier des Etangs}, A. and D. Magrin and R. Matson and Matthews, {E. C.} and Maxted, {P. F. L.} and S. McDermott and M. Munari and C. Mordasini and N. Narita and G. Olofsson and R. Ottensamer and I. Pagano and E. Pall{\`e} and G. Peter and D. Pollacco and D. Queloz and R. Ragazzoni and N. Rando and F. Ratti and H. Rauer and I. Ribas and S. Salmon and Santos, {N. C.} and G. Scandariato and S. Seager and D. S{\`e}gransan and Smith, {A. M. S.} and J. Schlieder and Schwarz, {R. P.} and A. Shporer and Sousa, {S. G.} and M. Stalport and M. Steinberger and S. Sulis and Szab{\`o}, {Gy M.} and Twicken, {J. D.} and S. Udry and {Van Grootel}, V. and J. Venturini and E. Villaver and Walton, {N. A.} and Winn, {J. N.}",

note = "Funding: LBo, GBr, VNa, IPa, GPi, RRa, GSc, VSi, and TZi acknowledge support from CHEOPS ASI-INAF agreement no. 2019-29-HH.0. TZi acknowledges NVIDIA Academic Hardware Grant Program for the use of the Titan V GPU card and the Italian MUR Departments of Excellence grant 2023-2027 “Quantum Frontiers”. C.B. acknowledges support from the Swiss Space Office through the ESA PRODEX program. This work has been carried out within the framework of the NCCR PlanetS supported by the Swiss National Science Foundation under grants 51NF40_182901 and 51NF40_205606. ML acknowledges support of the Swiss National Science Foundation under grant number PCEFP2_194576. A.S. acknowledges support from the Swiss Space Office through the ESA PRODEX program. YAl acknowledges support from the Swiss National Science Foundation (SNSF) under grant 200020_192038. The Belgian participation to CHEOPS has been supported by the Belgian Federal Science Policy Office (BELSPO) in the framework of the PRODEX Program, and by the University of Li{\`e}ge through an ARC grant for Concerted Research Actions financed by the Wallonia-Brussels Federation. L.D. thanks the Belgian Federal Science Policy Office (BELSPO) for the provision of financial support in the framework of the PRODEX Programme of the European Space Agency (ESA) under contract number 4000142531. ABr was supported by the SNSA. ACMC acknowledges support from the FCT, Portugal, through the CFisUC projects UIDB/04564/2020 and UIDP/04564/2020, with DOI identifiers 10.54499/UIDB/04564/2020 and 10.54499/UIDP/04564/2020, respectively. This work has been supported by the PRIN-INAF 2019 “Planetary systems at young ages (PLATEA)”. We acknowledge financial support from the Agencia Estatal de Investigaci{\'o}n of the Ministerio de Ciencia e Innovaci{\'o}n MCIN/AEI/10.13039/501100011033 and the ERDF “A way of making Europe” through projects PID2019-107061GB-C61, PID2019-107061GB-C66, PID2021- 125627OB-C31, and PID2021-125627OB-C32, from the Centre of Excellence “Severo Ochoa” award to the Instituto de Astrof{\'i}sica de Canarias (CEX2019- 000920-S), from the Centre of Excellence “Mar{\'i}a de Maeztu” award to the Institut de Ci{\`e}ncies de l{\textquoteright}Espai (CEX2020-001058-M), and from the Generali- tat de Catalunya/CERCA programme. We acknowledge financial support from the Agencia Estatal de Investigaci{\'o}n of the Ministerio de Ciencia e Innovaci{\'o}n MCIN/AEI/10.13039/501100011033 and the ERDF “A way of making Europe” through projects PID2019-107061GB-C61, PID2019-107061GB-C66, PID2021- 125627OB-C31, and PID2021-125627OB-C32, from the Centre of Excellence “Severo Ochoa” award to the Instituto de Astrof{\'i}sica de Canarias (CEX2019- 000920-S), from the Centre of Excellence “Mar{\'i}a de Maeztu” award to the Institut de Ci{\`e}ncies de l{\textquoteright}Espai (CEX2020-001058-M), and from the General- itat de Catalunya/CERCA programme. S.C.C.B. acknowledges support from FCT through FCT contracts nr. IF/01312/2014/CP1215/CT0004. ACC acknowledges support from STFC consolidated grant number ST/V000861/1, and UKSA grant number ST/X002217/1. P.E.C. is funded by the Austrian Science Fund (FWF) Erwin Schroedinger Fellowship, program J4595-N. This project was supported by the CNES. This work was supported by FCT – Funda{\c c}{\~a}o para a Ci{\^e}ncia e a Tecnologia through national funds and by FEDER through COM- PETE2020 through the research grants UIDB/04434/2020, UIDP/04434/2020, 2022.06962.PTDC. O.D.S.D. is supported in the form of work contract (DL 57/2016/CP1364/CT0004) funded by national funds through FCT. B.- O. D. acknowledges support from the Swiss State Secretariat for Education, Research and Innovation (SERI) under contract number MB22.00046. This project has received funding from the Swiss National Science Foundation for project 200021_200726. It has also been carried out within the framework of the National Centre of Competence in Research PlanetS supported by the Swiss National Science Foundation under grant 51NF40_205606. The authors acknowledge the financial support of the SNSF. M.F. and C.M.P. gratefully acknowledge the support of the Swedish National Space Agency (DNR 65/19, 174/18). D.D. acknowledges support from the TESS Guest Investigator Program grant 80NSSC23K0769. DG gratefully acknowledges financial support from the CRT foundation under Grant No. 2018.2323 “Gaseous or rocky? Unveiling the nature of small worlds”. D.P. acknowledges the support from the Isti- tuto Nazionale di Oceanografia e Geofisica Sperimentale (OGS) and CINECA through the program “HPC-TRES (High Performance Computing Training and Research for Earth Sciences)” award number 2022-05 as well as the support of the ASI-INAF agreement No. 2021-5-HH.1-2022. DT acknowledges the support from the European Research Council via the Horizon 2020 Framework Programme ERC Synergy “ECOGAL” Project GA-855130. DRC acknowledges partial support from NASA Grant 18-2XRP18_2-0007. This research has made use of the Exoplanet Follow-up Observation Program (ExoFOP; DOI: 10.26134/Exo- FOP5) website, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. Some of the data presented herein were obtained at Keck Observatory, which is a private 501(c)3 non-profit organization operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the Native Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. M.G. is an F.R.S.- FNRS Senior Research Associate. MNG is the ESA CHEOPS Project Scientist and Mission Representative, and as such also responsible for the Guest Observers (GO) Programme. MNG does not relay proprietary information between the GO and Guaranteed Time Observation (GTO) Programmes, and does not decide on the definition and target selection of the GTO Programme. MP acknowledge support from the European Union – NextGenerationEU (PRIN MUR 2022 20229R43BH) and the {"}Programma di Ricerca Fondamentale INAF 2023. CHe acknowledges support from the European Union H2020-MSCA-ITN-2019 under Grant Agreement no. 860470 (CHAMELEON). KGI is the ESA CHEOPS Project Scientist and is responsible for the ESA CHEOPS Guest Observers Programme. She does not participate in, or contribute to, the definition of the Guaranteed Time Programme of the CHEOPS mission through which observations described in this paper have been taken, nor to any aspect of target selection for the programme. K.W.F.L. was supported by Deutsche Forschungsgemein- schaft grants RA714/14-1 within the DFG Schwerpunkt SPP 1992, Exploring the Diversity of Extrasolar Planets. This work was granted access to the HPC resources of MesoPSL financed by the Region Ile de France and the project Equip@Meso (reference ANR-10-EQPX-29-01) of the programme Investisse- ments d{\textquoteright}Avenir supervised by the Agence Nationale pour la Recherche. P.M. acknowledges support from STFC research grant number ST/R000638/1. This work was also partially supported by a grant from the Simons Foundation (PI Queloz, grant number 327127). NCSa acknowledges funding by the European Union (ERC, FIERCE, 101052347). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Research Council. Neither the European Union nor the granting authority can be held responsible for them. S.G.S. acknowledge support from FCT through FCT contract nr. CEECIND/00826/2018 and POPH/FSE (EC). The Portuguese team thanks the Portuguese Space Agency for the provision of financial support in the framework of the PRODEX Programme of the European Space Agency (ESA) under contract number 4000142255. GyMSz acknowledges the support of the Hungarian National Research, Development and Innovation Office (NKFIH) grant K-125015, a a PRODEX Experiment Agreement No. 4000137122, the Lend{\"u}let LP2018-7/2021 grant of the Hungarian Academy of Science and the support of the city of Szombathely. V.V.G. is an F.R.S-FNRS Research Associate. JV acknowledges support from the Swiss National Science Foundation (SNSF) under grant PZ00P2_208945. NAW acknowledges UKSA grant ST/R004838/1. TWi acknowledges support from the UKSA and the University of Warwick. KAC acknowledges support from the TESS mission via subaward s3449 from MIT. Funding for the TESS mission is provided by NASA{\textquoteright}s Science Mission Directorate. 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. TESS data presented in this paper were obtained from the Mikulski Archive for Space Telescopes (MAST) at the Space Telescope Science Institute. This research has made use of the Exoplanet Follow-up Observation Program (ExoFOP; DOI: 10.26134/ExoFOP5) website, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. Co-funded by the European Union (ERC, FIERCE, 101052347). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Research Council. Neither the European Union nor the granting authority can be held responsible for them. This work was supported by FCT – Fun- da{\c c}{\~a}o para a Ci{\^e}ncia e a Tecnologia through national funds and by FEDER through COMPETE2020 – Programa Operacional Competitividade e Interna- cionaliza{\c c}{\~a}o by these grants: UIDB/04434/2020; UIDP/04434/2020. This work makes use of observations from the LCOGT network. Part of the LCOGT telescope time was granted by NOIRLab through the Mid-Scale Innovations Program (MSIP). MSIP is funded by NSF. This is paper is based on observations made with the MuSCAT3 instrument, developed by the Astrobiology Center and under financial supports by JSPS KAKENHI (JP18H05439) and JST PRESTO (JPMJPR1775), at Faulkes Telescope North on Maui, HI, operated by the Las Cumbres Observatory. This work is partly supported by JSPS KAKENHI Grant Number JP24H00017 and JSPS Bilateral Program Number JPJSBP120249910.",

year = "2025",

month = mar,

day = "31",

doi = "10.1051/0004-6361/202451180",

language = "English",

volume = "695",

journal = "Astronomy & Astrophysics",

issn = "0004-6361",

publisher = "EDP Sciences",

}

Zingales, T, Malavolta, L, Borsato, L, Turrini, D, Bonfanti, A, Polychroni, D, Mantovan, G, Nardiello, D, Nascimbeni, V, Lanza, AF, Bekkelien, A, Sozzetti, A, Broeg, C, Naponiello, L, Lendl, M, Bonomo, AS, Simon, AE, Desidera, S, Piotto, G, Mancini, L, Hooton, MJ, Bignamini, A, Egger, JA, Maggio, A, Alibert, Y, Locci, D, Delrez, L, Biassoni, F, Fossati, L, Cabona, L, Lacedelli, G, Carleo, I, Leonardi, P, Andreuzzi, G, Brandeker, A, Cosentino, R, Correia, ACM, Claudi, R, Alonso, R, Damasso, M, Wilson, TG, Bàrczy, T, Pinamonti, M, Baker, D, Barkaoui, K, Barrado Navascues, D, Barros, SCC, Baumjohann, W, Beck, T, Beichman, C, Benz, W, Bieryla, A, Billot, N, Bosch-Cabot, P, Bouma, LG, Ciardi, DR, Cameron, AC, Collins, KA, Crossfield, IJM, Csizmadia, S, Cubillos, PE, Davies, MB, Deleuil, M, Deline, A, Demangeon, ODS, Demory, B-O, Derekas, A, Dragomir, D, Edwards, B, Ehrenreich, D, Erikson, A, Falk, B, Fortier, A, Fridlund, M, Fukui, A, Gandolfi, D, Gazeas, K, Gillon, M, Gonzales, E, Gudel, M, Guerra, P, Günther, MN, Heitzmann, A, Helling, C, Howell, SB, Isaak, KG, Jenkins, J, Kiss, LL, Korth, J, Lam, KWF, Laskar, J, Lecavelier des Etangs, A, Magrin, D, Matson, R, Matthews, EC, Maxted, PFL, McDermott, S, Munari, M, Mordasini, C, Narita, N, Olofsson, G, Ottensamer, R, Pagano, I, Pallè, E, Peter, G, Pollacco, D, Queloz, D, Ragazzoni, R, Rando, N, Ratti, F, Rauer, H, Ribas, I, Salmon, S, Santos, NC, Scandariato, G, Seager, S, Sègransan, D, Smith, AMS, Schlieder, J, Schwarz, RP, Shporer, A, Sousa, SG, Stalport, M, Steinberger, M, Sulis, S, Szabò, GM, Twicken, JD, Udry, S, Van Grootel, V, Venturini, J, Villaver, E, Walton, NA & Winn, JN 2025, 'A joint effort to discover and characterize two resonant mini-Neptunes around TOI-1803 with TESS, HARPS-N, and CHEOPS', Astronomy & Astrophysics, vol. 695, A273. https://doi.org/10.1051/0004-6361/202451180

TY - JOUR

T1 - A joint effort to discover and characterize two resonant mini-Neptunes around TOI-1803 with TESS, HARPS-N, and CHEOPS

AU - Zingales, T.

AU - Malavolta, L.

AU - Borsato, L.

AU - Turrini, D.

AU - Bonfanti, A.

AU - Polychroni, D.

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N1 - Funding: LBo, GBr, VNa, IPa, GPi, RRa, GSc, VSi, and TZi acknowledge support from CHEOPS ASI-INAF agreement no. 2019-29-HH.0. TZi acknowledges NVIDIA Academic Hardware Grant Program for the use of the Titan V GPU card and the Italian MUR Departments of Excellence grant 2023-2027 “Quantum Frontiers”. C.B. acknowledges support from the Swiss Space Office through the ESA PRODEX program. This work has been carried out within the framework of the NCCR PlanetS supported by the Swiss National Science Foundation under grants 51NF40_182901 and 51NF40_205606. ML acknowledges support of the Swiss National Science Foundation under grant number PCEFP2_194576. A.S. acknowledges support from the Swiss Space Office through the ESA PRODEX program. YAl acknowledges support from the Swiss National Science Foundation (SNSF) under grant 200020_192038. The Belgian participation to CHEOPS has been supported by the Belgian Federal Science Policy Office (BELSPO) in the framework of the PRODEX Program, and by the University of Liège through an ARC grant for Concerted Research Actions financed by the Wallonia-Brussels Federation. L.D. thanks the Belgian Federal Science Policy Office (BELSPO) for the provision of financial support in the framework of the PRODEX Programme of the European Space Agency (ESA) under contract number 4000142531. ABr was supported by the SNSA. ACMC acknowledges support from the FCT, Portugal, through the CFisUC projects UIDB/04564/2020 and UIDP/04564/2020, with DOI identifiers 10.54499/UIDB/04564/2020 and 10.54499/UIDP/04564/2020, respectively. This work has been supported by the PRIN-INAF 2019 “Planetary systems at young ages (PLATEA)”. We acknowledge financial support from the Agencia Estatal de Investigación of the Ministerio de Ciencia e Innovación MCIN/AEI/10.13039/501100011033 and the ERDF “A way of making Europe” through projects PID2019-107061GB-C61, PID2019-107061GB-C66, PID2021- 125627OB-C31, and PID2021-125627OB-C32, from the Centre of Excellence “Severo Ochoa” award to the Instituto de Astrofísica de Canarias (CEX2019- 000920-S), from the Centre of Excellence “María de Maeztu” award to the Institut de Ciències de l’Espai (CEX2020-001058-M), and from the Generali- tat de Catalunya/CERCA programme. We acknowledge financial support from the Agencia Estatal de Investigación of the Ministerio de Ciencia e Innovación MCIN/AEI/10.13039/501100011033 and the ERDF “A way of making Europe” through projects PID2019-107061GB-C61, PID2019-107061GB-C66, PID2021- 125627OB-C31, and PID2021-125627OB-C32, from the Centre of Excellence “Severo Ochoa” award to the Instituto de Astrofísica de Canarias (CEX2019- 000920-S), from the Centre of Excellence “María de Maeztu” award to the Institut de Ciències de l’Espai (CEX2020-001058-M), and from the General- itat de Catalunya/CERCA programme. S.C.C.B. acknowledges support from FCT through FCT contracts nr. IF/01312/2014/CP1215/CT0004. ACC acknowledges support from STFC consolidated grant number ST/V000861/1, and UKSA grant number ST/X002217/1. P.E.C. is funded by the Austrian Science Fund (FWF) Erwin Schroedinger Fellowship, program J4595-N. This project was supported by the CNES. This work was supported by FCT – Fundação para a Ciência e a Tecnologia through national funds and by FEDER through COM- PETE2020 through the research grants UIDB/04434/2020, UIDP/04434/2020, 2022.06962.PTDC. O.D.S.D. is supported in the form of work contract (DL 57/2016/CP1364/CT0004) funded by national funds through FCT. B.- O. D. acknowledges support from the Swiss State Secretariat for Education, Research and Innovation (SERI) under contract number MB22.00046. This project has received funding from the Swiss National Science Foundation for project 200021_200726. It has also been carried out within the framework of the National Centre of Competence in Research PlanetS supported by the Swiss National Science Foundation under grant 51NF40_205606. The authors acknowledge the financial support of the SNSF. M.F. and C.M.P. gratefully acknowledge the support of the Swedish National Space Agency (DNR 65/19, 174/18). D.D. acknowledges support from the TESS Guest Investigator Program grant 80NSSC23K0769. DG gratefully acknowledges financial support from the CRT foundation under Grant No. 2018.2323 “Gaseous or rocky? Unveiling the nature of small worlds”. D.P. acknowledges the support from the Isti- tuto Nazionale di Oceanografia e Geofisica Sperimentale (OGS) and CINECA through the program “HPC-TRES (High Performance Computing Training and Research for Earth Sciences)” award number 2022-05 as well as the support of the ASI-INAF agreement No. 2021-5-HH.1-2022. DT acknowledges the support from the European Research Council via the Horizon 2020 Framework Programme ERC Synergy “ECOGAL” Project GA-855130. DRC acknowledges partial support from NASA Grant 18-2XRP18_2-0007. This research has made use of the Exoplanet Follow-up Observation Program (ExoFOP; DOI: 10.26134/Exo- FOP5) website, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. Some of the data presented herein were obtained at Keck Observatory, which is a private 501(c)3 non-profit organization operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the Native Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. M.G. is an F.R.S.- FNRS Senior Research Associate. MNG is the ESA CHEOPS Project Scientist and Mission Representative, and as such also responsible for the Guest Observers (GO) Programme. MNG does not relay proprietary information between the GO and Guaranteed Time Observation (GTO) Programmes, and does not decide on the definition and target selection of the GTO Programme. MP acknowledge support from the European Union – NextGenerationEU (PRIN MUR 2022 20229R43BH) and the "Programma di Ricerca Fondamentale INAF 2023. CHe acknowledges support from the European Union H2020-MSCA-ITN-2019 under Grant Agreement no. 860470 (CHAMELEON). KGI is the ESA CHEOPS Project Scientist and is responsible for the ESA CHEOPS Guest Observers Programme. She does not participate in, or contribute to, the definition of the Guaranteed Time Programme of the CHEOPS mission through which observations described in this paper have been taken, nor to any aspect of target selection for the programme. K.W.F.L. was supported by Deutsche Forschungsgemein- schaft grants RA714/14-1 within the DFG Schwerpunkt SPP 1992, Exploring the Diversity of Extrasolar Planets. This work was granted access to the HPC resources of MesoPSL financed by the Region Ile de France and the project Equip@Meso (reference ANR-10-EQPX-29-01) of the programme Investisse- ments d’Avenir supervised by the Agence Nationale pour la Recherche. P.M. acknowledges support from STFC research grant number ST/R000638/1. This work was also partially supported by a grant from the Simons Foundation (PI Queloz, grant number 327127). NCSa acknowledges funding by the European Union (ERC, FIERCE, 101052347). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Research Council. Neither the European Union nor the granting authority can be held responsible for them. S.G.S. acknowledge support from FCT through FCT contract nr. CEECIND/00826/2018 and POPH/FSE (EC). The Portuguese team thanks the Portuguese Space Agency for the provision of financial support in the framework of the PRODEX Programme of the European Space Agency (ESA) under contract number 4000142255. GyMSz acknowledges the support of the Hungarian National Research, Development and Innovation Office (NKFIH) grant K-125015, a a PRODEX Experiment Agreement No. 4000137122, the Lendület LP2018-7/2021 grant of the Hungarian Academy of Science and the support of the city of Szombathely. V.V.G. is an F.R.S-FNRS Research Associate. JV acknowledges support from the Swiss National Science Foundation (SNSF) under grant PZ00P2_208945. NAW acknowledges UKSA grant ST/R004838/1. TWi acknowledges support from the UKSA and the University of Warwick. KAC acknowledges support from the TESS mission via subaward s3449 from MIT. Funding for the TESS mission is provided by NASA’s Science Mission Directorate. 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. TESS data presented in this paper were obtained from the Mikulski Archive for Space Telescopes (MAST) at the Space Telescope Science Institute. This research has made use of the Exoplanet Follow-up Observation Program (ExoFOP; DOI: 10.26134/ExoFOP5) website, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. Co-funded by the European Union (ERC, FIERCE, 101052347). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Research Council. Neither the European Union nor the granting authority can be held responsible for them. This work was supported by FCT – Fun- dação para a Ciência e a Tecnologia through national funds and by FEDER through COMPETE2020 – Programa Operacional Competitividade e Interna- cionalização by these grants: UIDB/04434/2020; UIDP/04434/2020. This work makes use of observations from the LCOGT network. Part of the LCOGT telescope time was granted by NOIRLab through the Mid-Scale Innovations Program (MSIP). MSIP is funded by NSF. This is paper is based on observations made with the MuSCAT3 instrument, developed by the Astrobiology Center and under financial supports by JSPS KAKENHI (JP18H05439) and JST PRESTO (JPMJPR1775), at Faulkes Telescope North on Maui, HI, operated by the Las Cumbres Observatory. This work is partly supported by JSPS KAKENHI Grant Number JP24H00017 and JSPS Bilateral Program Number JPJSBP120249910.

PY - 2025/3/31

Y1 - 2025/3/31

N2 - Context. The discovery and characterization of mini-Neptunes hold a potentially crucial impact on planetary formation and evolution theories. Estimating their orbital parameters and atmospheric properties would provide valuable hints to improve formation and atmospheric models.Aims. We present the discovery of two mini-Neptunes near a 2:1 orbital resonance configuration orbiting the K0 star TOI-1803. We describe in detail their orbital architecture and suggest some possible formation and evolution scenarios.Methods. Using CHEOPS, TESS, and HARPS-N datasets, we estimated the radius and the mass of both planets. We used a multidimensional Gaussian process with a quasi-periodic kernel to disentangle the planetary components from the stellar activity in the HARPS-N dataset. We performed dynamical modeling to explain the orbital configuration and performed planetary formation and evolution simulations. For the least dense planet, we assumed different atmospheric compositions and defined possible atmospheric scenarios with simulated JWST observations.Results. TOI-1803 b and TOI-1803 c have orbital periods of ∼6.3 and ∼12.9 days, respectively, residing in close proximity to a 2:1 orbital resonance. Ground-based photometric follow-up observations have revealed significant transit timing variations (TTV) with an amplitude of ∼10 min and ∼40 min, respectively, for planets b and -c. With the masses computed from the radial velocities dataset, we obtained a density of (0.39 ± 0.10) ρ⊕ and (0.076 ± 0.038) ρ⊕ for planets b and -c, respectively. TOI-1803 c is among the least dense mini-Neptunes currently known, and due to its inflated atmosphere, it is a suitable target for transmission spectroscopy with JWST. With NIRSpec observations, we could understand whether the planet has kept its primary atmosphere or not, which would constrain our formation models.Conclusions. We report the discovery of two mini-Neptunes close to a 2:1 orbital resonance. The detection of significant TTVs from ground-based photometry opens scenarios for a more precise mass determination. TOI-1803 c is one of the least dense mini-Neptunes known so far, and it is of great interest among the scientific community since it could constrain current formation scenarios. JWST observations could give us valuable insights to characterize this interesting system.

AB - Context. The discovery and characterization of mini-Neptunes hold a potentially crucial impact on planetary formation and evolution theories. Estimating their orbital parameters and atmospheric properties would provide valuable hints to improve formation and atmospheric models.Aims. We present the discovery of two mini-Neptunes near a 2:1 orbital resonance configuration orbiting the K0 star TOI-1803. We describe in detail their orbital architecture and suggest some possible formation and evolution scenarios.Methods. Using CHEOPS, TESS, and HARPS-N datasets, we estimated the radius and the mass of both planets. We used a multidimensional Gaussian process with a quasi-periodic kernel to disentangle the planetary components from the stellar activity in the HARPS-N dataset. We performed dynamical modeling to explain the orbital configuration and performed planetary formation and evolution simulations. For the least dense planet, we assumed different atmospheric compositions and defined possible atmospheric scenarios with simulated JWST observations.Results. TOI-1803 b and TOI-1803 c have orbital periods of ∼6.3 and ∼12.9 days, respectively, residing in close proximity to a 2:1 orbital resonance. Ground-based photometric follow-up observations have revealed significant transit timing variations (TTV) with an amplitude of ∼10 min and ∼40 min, respectively, for planets b and -c. With the masses computed from the radial velocities dataset, we obtained a density of (0.39 ± 0.10) ρ⊕ and (0.076 ± 0.038) ρ⊕ for planets b and -c, respectively. TOI-1803 c is among the least dense mini-Neptunes currently known, and due to its inflated atmosphere, it is a suitable target for transmission spectroscopy with JWST. With NIRSpec observations, we could understand whether the planet has kept its primary atmosphere or not, which would constrain our formation models.Conclusions. We report the discovery of two mini-Neptunes close to a 2:1 orbital resonance. The detection of significant TTVs from ground-based photometry opens scenarios for a more precise mass determination. TOI-1803 c is one of the least dense mini-Neptunes known so far, and it is of great interest among the scientific community since it could constrain current formation scenarios. JWST observations could give us valuable insights to characterize this interesting system.

KW - Planets and satellites: detection

KW - Planets and satellites: dynamical evolution and stability

KW - Planets and satellites: formation

KW - Planets and satellites: fundamental parameters

KW - Planets and satellites: interiors

U2 - 10.1051/0004-6361/202451180

DO - 10.1051/0004-6361/202451180

M3 - Article

SN - 0004-6361

VL - 695

JO - Astronomy & Astrophysics

JF - Astronomy & Astrophysics

M1 - A273

ER -

A joint effort to discover and characterize two resonant mini-Neptunes around TOI-1803 with TESS, HARPS-N, and CHEOPS

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AO2 - Professor Andrew Cameron: Project AO2 - Andrew Cameron

H2020 MSCA ITN EJD 2019: H2020 MSCA ITN EJD 2019 CHAMELEON

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