Characterisation of the TOI-421 planetary system using CHEOPS, TESS, and archival radial velocity data

A. F. Krenn; D. Kubyshkina; L. Fossati; J. A. Egger; A. Bonfanti; A. Deline; D. Ehrenreich; M. Beck; W. Benz; J. Cabrera; T. G. Wilson; A. Leleu; S. G. Sousa; V. Adibekyan; A. C. M. Correira; Y. Alibert; L. Delrez; M. Lendl; J. A. Patel; J. Venturini; R. Alonso; G. Anglada; J. Asquier; T. Bárczy; D. Barrado Navascues; S. C. C. Barros; W. Baumjohann; T. Beck; N. Billot; X. Bonfils; L. Borsato; A. Brandeker; C. Broeg; S. Charnoz; A. Collier Cameron; Sz Csizmadia; P. E. Cubillos; M. B. Davies; M. Deleuil; O. D. S. Demangeon; B. -O. Demory; A. Erikson; A. Fortier; M. Fridlund; D. Gandolfi; M. Gillon; M. Güdel; M. N. Günther; J. Hasiba; A. Heitzmann; C. Helling; S. Hoyer; K. G. Isaak; L. L. Kiss; K. W. F. Lam; J. Laskar; A. Lecavelier des Etangs; C. Lovis; D. Magrin; P. F. L. Maxted; C. Mordasini; V. Nascimbeni; G. Olofsson; R. Ottensamer; I. Pagano; E. Pallé; G. Peter; G. Piotto; D. Pollacco; D. Queloz; R. Ragazzoni; N. Rando; H. Rauer; I. Ribas; M. Rieder; N. C. Santos; G. Scandariato; D. Ségransan; A. E. Simon; A. M. S. Smith; M. Stalport; M. Steller; Gy M. Szabó; N. Thomas; S. Udry; B. Ulmer; V. Van Grootel; E. Villaver; V. Viotto; N. A. Walton; T. Zingales

doi:10.1051/0004-6361/202348584

Characterisation of the TOI-421 planetary system using CHEOPS, TESS, and archival radial velocity data

A. F. Krenn^*, D. Kubyshkina, L. Fossati, J. A. Egger, A. Bonfanti, A. Deline, D. Ehrenreich, M. Beck, W. Benz, J. Cabrera, T. G. Wilson, A. Leleu, S. G. Sousa, V. Adibekyan, A. C. M. Correira, Y. Alibert, L. Delrez, M. Lendl, J. A. Patel, J. VenturiniR. Alonso, G. Anglada, J. Asquier, T. Bárczy, D. Barrado Navascues, S. C. C. Barros, W. Baumjohann, T. Beck, N. Billot, X. Bonfils, L. Borsato, A. Brandeker, C. Broeg, S. Charnoz, A. Collier Cameron, Sz Csizmadia, P. E. Cubillos, M. B. Davies, M. Deleuil, O. D. S. Demangeon, B. -O. Demory, A. Erikson, A. Fortier, M. Fridlund, D. Gandolfi, M. Gillon, M. Güdel, M. N. Günther, J. Hasiba, A. Heitzmann, C. Helling, S. Hoyer, K. G. Isaak, L. L. Kiss, K. W. F. Lam, J. Laskar, A. Lecavelier des Etangs, C. Lovis, D. Magrin, P. F. L. Maxted, C. Mordasini, V. Nascimbeni, G. Olofsson, R. Ottensamer, I. Pagano, E. Pallé, G. Peter, G. Piotto, D. Pollacco, D. Queloz, R. Ragazzoni, N. Rando, H. Rauer, I. Ribas, M. Rieder, N. C. Santos, G. Scandariato, D. Ségransan, A. E. Simon, A. M. S. Smith, M. Stalport, M. Steller, Gy M. Szabó, N. Thomas, S. Udry, B. Ulmer, V. Van Grootel, E. Villaver, V. Viotto, N. A. Walton, T. Zingales

^*Corresponding author for this work

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

Abstract

Context. The TOI-421 planetary system contains two sub-Neptune-type planets (P_b ~ 5.2 days, T_eq,b ~ 900 K, and P_c ~ 16.1 days, T_eq,c ~ 650 K) and is a prime target to study the formation and evolution of planets and their atmospheres. The inner planet is especially interesting as the existence of a hydrogen-dominated atmosphere at its orbital separation cannot be explained by current formation models without previous orbital migration.

Aims. We aim to improve the system parameters to further use them to model the interior structure and simulate the atmospheric evolution of both planets, to finally gain insights into their formation and evolution. We also investigate the possibility of detecting transit timing variations (TTVs).

Methods. We jointly analysed photometric data of three TESS sectors and six CHEOPS visits as well as 156 radial velocity data points to retrieve improved planetary parameters. We also searched for TTVs and modelled the interior structure of the planets. Finally, we simulated the evolution of the primordial H-He atmospheres of the planets using two different modelling frameworks.

Results. We determine the planetary radii and masses of TOI-421 b and c to be R_b = 2.64 ± 0.08 R⊕, Mb = 6.7 ± 0.6 M⊕, R_c = 5.09 ± 0.07 R⊕, and M_c = 14.1 ± 1.4 M⊕. Using these results we retrieved average planetary densities of ρ_b = 0.37 ± 0.05ρ⊕ and ρ_c = 0.107 ± 0.012 ρ⊕. We do not detect any statistically significant TTV signals. Assuming the presence of a hydrogen-dominated atmosphere, the interior structure modelling results in both planets having extensive envelopes. While the modelling of the atmospheric evolution predicts for TOI-421 b to have lost any primordial atmosphere that it could have accreted at its current orbital position, TOI-421 c could have started out with an initial atmospheric mass fraction somewhere between 10 and 35%.

Conclusions. We conclude that the low observed mean density of TOI-421 b can only be explained by either a bias in the measured planetary parameters (e.g. driven by high-altitude clouds) and/or in the context of orbital migration. We also find that the results of atmospheric evolution models are strongly dependent on the employed planetary structure model.

Original language	English
Article number	A301
Number of pages	20
Journal	Astronomy & Astrophysics
Volume	686
Early online date	25 Jun 2024
DOIs	https://doi.org/10.1051/0004-6361/202348584
Publication status	Published - Jun 2024

Keywords

Planets and satellites: composition
Planets and satellites: fundamental parameters
Planets and satellites: individual: TOI-421

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2 Finished

REVEAL: REVEALing Signatures of Habitable Worlds Hidden by Stellar Activity
Cameron, A. C. (PI)
UKRI (EU)
1/08/24 → 31/07/30
Project: Standard
AO2 - Professor Andrew Cameron: Project AO2 - Andrew Cameron
Cameron, A. C. (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
1/06/20 → 31/05/24
Project: Standard

TOI-421 light and velocity curves
Krenn, A. F. (Creator), Kubyshkina, D. (Creator), Fossati, L. (Creator), Egger, J. A. (Creator), Bonfanti, A. (Creator), Deline, A. (Creator), Ehrenreich, D. (Creator), Beck, M. (Creator), Benz, W. (Creator), Cabrera, J. (Creator), Wilson, T. G. (Creator), Leleu, A. (Creator), Sousa, S. G. (Creator), Adibekyan, V. (Creator), Correia, A. C. M. (Creator), Alibert, Y. (Creator), Delrez, L. (Creator), Lendl, M. (Creator), Patel, J. A. (Creator), Venturini, J. (Creator), Alonso, R. (Creator), Anglada, G. (Creator), Asquier, J. (Creator), Barczy, T. (Creator), Barrado Navascues, D. (Creator), Barros, S. C. C. (Creator), Baumjohann, W. (Creator), Beck, T. (Creator), Billot, N. (Creator), Bonfils, X. (Creator), Borsato, L. (Creator), Brandeker, A. (Creator), Broeg, C. (Creator), Charnoz, S. (Creator), Collier Cameron, A. (Creator), Sz, C. (Creator), Cubillos, P. E. (Creator), Davies, M. B. (Creator), Deleuil, M. (Creator), Demangeon, O. D. S. (Creator), Demory, B.-O. (Creator), Erikson, A. (Creator), Fortier, A. (Creator), Fridlund, M. (Creator), Gandolfi, D. (Creator), Gillon, M. (Creator), Guedel, M. (Creator), Guenther, M. N. (Creator), Hasiba, J. (Creator), Heitzmann, A. (Creator), Helling, C. (Creator), Hoyer, S. (Creator), Isaak, K. G. (Creator), Kiss, L. L. (Creator), K.W.F., L. (Creator), Laskar, J. (Creator), Lecavelier Des Etangs, A. (Creator), Lovis, C. (Creator), Magrin, D. (Creator), Maxted, P. F. L. (Creator), Mordasini, C. (Creator), Nascimbeni, V. (Creator), Olofsson, G. (Creator), Ottensamer, R. (Creator), Pagano, I. (Creator), Palle, E. (Creator), Peter, G. (Creator), Piotto, G. (Creator), Pollacco, D. (Creator), Queloz, D. (Creator), Ragazzoni, R. (Creator), Rando, N. (Creator), Rauer, H. (Creator), Ribas, I. (Creator), Rieder, M. (Creator), Santos, N. C. (Creator), Scandariato, G. (Creator), Segransan, D. (Creator), Simon, A. E. (Creator), Smith, A. M. S. (Creator), Stalport, M. (Creator), Steller, M. (Creator), GyM., S. (Creator), Thomas, N. (Creator), Udry, S. (Creator), Ulmer, B. (Creator), Van Grootel, V. (Creator), Villaver, E. (Creator), Viotto, V. (Creator), Walton, N. A. (Creator) & Zingales, T. (Creator), Centre de Donnees Strasbourg (CDS), 2024
DOI: 10.26093/cds/vizier.36860301
Dataset

Cite this

Krenn, A. F., Kubyshkina, D., Fossati, L., Egger, J. A., Bonfanti, A., Deline, A., Ehrenreich, D., Beck, M., Benz, W., Cabrera, J., Wilson, T. G., Leleu, A., Sousa, S. G., Adibekyan, V., Correira, A. C. M., Alibert, Y., Delrez, L., Lendl, M., Patel, J. A., ... Zingales, T. (2024). Characterisation of the TOI-421 planetary system using CHEOPS, TESS, and archival radial velocity data. Astronomy & Astrophysics, 686, Article A301. https://doi.org/10.1051/0004-6361/202348584

@article{377c8129f99a4f2ca8e36f343f0c8228,

title = "Characterisation of the TOI-421 planetary system using CHEOPS, TESS, and archival radial velocity data",

abstract = "Context. The TOI-421 planetary system contains two sub-Neptune-type planets (Pb ~ 5.2 days, Teq,b ~ 900 K, and Pc ~ 16.1 days, Teq,c ~ 650 K) and is a prime target to study the formation and evolution of planets and their atmospheres. The inner planet is especially interesting as the existence of a hydrogen-dominated atmosphere at its orbital separation cannot be explained by current formation models without previous orbital migration.Aims. We aim to improve the system parameters to further use them to model the interior structure and simulate the atmospheric evolution of both planets, to finally gain insights into their formation and evolution. We also investigate the possibility of detecting transit timing variations (TTVs).Methods. We jointly analysed photometric data of three TESS sectors and six CHEOPS visits as well as 156 radial velocity data points to retrieve improved planetary parameters. We also searched for TTVs and modelled the interior structure of the planets. Finally, we simulated the evolution of the primordial H-He atmospheres of the planets using two different modelling frameworks.Results. We determine the planetary radii and masses of TOI-421 b and c to be Rb = 2.64 ± 0.08 R⊕, Mb = 6.7 ± 0.6 M⊕, Rc = 5.09 ± 0.07 R⊕, and Mc = 14.1 ± 1.4 M⊕. Using these results we retrieved average planetary densities of ρb = 0.37 ± 0.05ρ⊕ and ρc = 0.107 ± 0.012 ρ⊕. We do not detect any statistically significant TTV signals. Assuming the presence of a hydrogen-dominated atmosphere, the interior structure modelling results in both planets having extensive envelopes. While the modelling of the atmospheric evolution predicts for TOI-421 b to have lost any primordial atmosphere that it could have accreted at its current orbital position, TOI-421 c could have started out with an initial atmospheric mass fraction somewhere between 10 and 35%.Conclusions. We conclude that the low observed mean density of TOI-421 b can only be explained by either a bias in the measured planetary parameters (e.g. driven by high-altitude clouds) and/or in the context of orbital migration. We also find that the results of atmospheric evolution models are strongly dependent on the employed planetary structure model.",

keywords = "Planets and satellites: composition, Planets and satellites: fundamental parameters, Planets and satellites: individual: TOI-421",

author = "Krenn, {A. F.} and D. Kubyshkina and L. Fossati and Egger, {J. A.} and A. Bonfanti and A. Deline and D. Ehrenreich and M. Beck and W. Benz and J. Cabrera and Wilson, {T. G.} and A. Leleu and Sousa, {S. G.} and V. Adibekyan and Correira, {A. C. M.} and Y. Alibert and L. Delrez and M. Lendl and Patel, {J. A.} and J. Venturini and R. Alonso and G. Anglada and J. Asquier and T. B{\'a}rczy and {Barrado Navascues}, D. and Barros, {S. C. C.} and W. Baumjohann and T. Beck and N. Billot and X. Bonfils and L. Borsato and A. Brandeker and C. Broeg and S. Charnoz and Cameron, {A. Collier} and Sz Csizmadia and Cubillos, {P. E.} and Davies, {M. B.} and M. Deleuil and Demangeon, {O. D. S.} and Demory, {B. -O.} and A. Erikson and A. Fortier and M. Fridlund and D. Gandolfi and M. Gillon and M. G{\"u}del and G{\"u}nther, {M. N.} and J. Hasiba and A. Heitzmann and C. Helling and S. Hoyer and Isaak, {K. G.} and Kiss, {L. L.} and Lam, {K. W. F.} and J. Laskar and {Lecavelier des Etangs}, A. and C. Lovis and D. Magrin and Maxted, {P. F. L.} and C. Mordasini and V. Nascimbeni and G. Olofsson and R. Ottensamer and I. Pagano and E. Pall{\'e} and G. Peter and G. Piotto and D. Pollacco and D. Queloz and R. Ragazzoni and N. Rando and H. Rauer and I. Ribas and M. Rieder and Santos, {N. C.} and G. Scandariato and D. S{\'e}gransan and Simon, {A. E.} and Smith, {A. M. S.} and M. Stalport and M. Steller and Szab{\'o}, {Gy M.} and N. Thomas and S. Udry and B. Ulmer and {Van Grootel}, V. and E. Villaver and V. Viotto and Walton, {N. A.} and T. Zingales",

note = "Funding: ACC acknowledge support from STFC consolidated grant numbers ST/R000824/1 and ST/V000861/1, and UKSA grant number ST/R003203/1. This project has received funding from the European Research Council (ERC) under the European Union{\textquoteright}s Horizon 2020 research and innovation programme (project FOUR ACES. grant agreement no. 724427). CHe acknowledges support from the European Union H2020-MSCA-ITN-2019 under Grant Agreement no. 860470 (CHAMELEON). P.M. acknowledges support from STFC research grant number ST/M001040/1. NCSa acknowledges funding by the European Union (ERC, FIERCE, 101052347). N.A.W. acknowledges UKSA grant ST/R004838/1.",

year = "2024",

month = jun,

doi = "10.1051/0004-6361/202348584",

language = "English",

volume = "686",

journal = "Astronomy & Astrophysics",

issn = "0004-6361",

publisher = "EDP SCIENCES S A",

}

Krenn, AF, Kubyshkina, D, Fossati, L, Egger, JA, Bonfanti, A, Deline, A, Ehrenreich, D, Beck, M, Benz, W, Cabrera, J, Wilson, TG, Leleu, A, Sousa, SG, Adibekyan, V, Correira, ACM, Alibert, Y, Delrez, L, Lendl, M, Patel, JA, Venturini, J, Alonso, R, Anglada, G, Asquier, J, Bárczy, T, Barrado Navascues, D, Barros, SCC, Baumjohann, W, Beck, T, Billot, N, Bonfils, X, Borsato, L, Brandeker, A, Broeg, C, Charnoz, S, Cameron, AC, Csizmadia, S, Cubillos, PE, Davies, MB, Deleuil, M, Demangeon, ODS, Demory, B-O, Erikson, A, Fortier, A, Fridlund, M, Gandolfi, D, Gillon, M, Güdel, M, Günther, MN, Hasiba, J, Heitzmann, A, Helling, C, Hoyer, S, Isaak, KG, Kiss, LL, Lam, KWF, Laskar, J, Lecavelier des Etangs, A, Lovis, C, Magrin, D, Maxted, PFL, Mordasini, C, Nascimbeni, V, Olofsson, G, Ottensamer, R, Pagano, I, Pallé, E, Peter, G, Piotto, G, Pollacco, D, Queloz, D, Ragazzoni, R, Rando, N, Rauer, H, Ribas, I, Rieder, M, Santos, NC, Scandariato, G, Ségransan, D, Simon, AE, Smith, AMS, Stalport, M, Steller, M, Szabó, GM, Thomas, N, Udry, S, Ulmer, B, Van Grootel, V, Villaver, E, Viotto, V, Walton, NA & Zingales, T 2024, 'Characterisation of the TOI-421 planetary system using CHEOPS, TESS, and archival radial velocity data', Astronomy & Astrophysics, vol. 686, A301. https://doi.org/10.1051/0004-6361/202348584

TY - JOUR

T1 - Characterisation of the TOI-421 planetary system using CHEOPS, TESS, and archival radial velocity data

AU - Krenn, A. F.

AU - Kubyshkina, D.

AU - Fossati, L.

AU - Egger, J. A.

AU - Bonfanti, A.

AU - Deline, A.

AU - Ehrenreich, D.

AU - Beck, M.

AU - Benz, W.

AU - Cabrera, J.

AU - Wilson, T. G.

AU - Leleu, A.

AU - Sousa, S. G.

AU - Adibekyan, V.

AU - Correira, A. C. M.

AU - Alibert, Y.

AU - Delrez, L.

AU - Lendl, M.

AU - Patel, J. A.

AU - Venturini, J.

AU - Alonso, R.

AU - Anglada, G.

AU - Asquier, J.

AU - Bárczy, T.

AU - Barrado Navascues, D.

AU - Barros, S. C. C.

AU - Baumjohann, W.

AU - Beck, T.

AU - Billot, N.

AU - Bonfils, X.

AU - Borsato, L.

AU - Brandeker, A.

AU - Broeg, C.

AU - Charnoz, S.

AU - Cameron, A. Collier

AU - Csizmadia, Sz

AU - Cubillos, P. E.

AU - Davies, M. B.

AU - Deleuil, M.

AU - Demangeon, O. D. S.

AU - Demory, B. -O.

AU - Erikson, A.

AU - Fortier, A.

AU - Fridlund, M.

AU - Gandolfi, D.

AU - Gillon, M.

AU - Güdel, M.

AU - Günther, M. N.

AU - Hasiba, J.

AU - Heitzmann, A.

AU - Helling, C.

AU - Hoyer, S.

AU - Isaak, K. G.

AU - Kiss, L. L.

AU - Lam, K. W. F.

AU - Laskar, J.

AU - Lecavelier des Etangs, A.

AU - Lovis, C.

AU - Magrin, D.

AU - Maxted, P. F. L.

AU - Mordasini, C.

AU - Nascimbeni, V.

AU - Olofsson, G.

AU - Ottensamer, R.

AU - Pagano, I.

AU - Pallé, E.

AU - Peter, G.

AU - Piotto, G.

AU - Pollacco, D.

AU - Queloz, D.

AU - Ragazzoni, R.

AU - Rando, N.

AU - Rauer, H.

AU - Ribas, I.

AU - Rieder, M.

AU - Santos, N. C.

AU - Scandariato, G.

AU - Ségransan, D.

AU - Simon, A. E.

AU - Smith, A. M. S.

AU - Stalport, M.

AU - Steller, M.

AU - Szabó, Gy M.

AU - Thomas, N.

AU - Udry, S.

AU - Ulmer, B.

AU - Van Grootel, V.

AU - Villaver, E.

AU - Viotto, V.

AU - Walton, N. A.

AU - Zingales, T.

N1 - Funding: ACC acknowledge support from STFC consolidated grant numbers ST/R000824/1 and ST/V000861/1, and UKSA grant number ST/R003203/1. 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). CHe acknowledges support from the European Union H2020-MSCA-ITN-2019 under Grant Agreement no. 860470 (CHAMELEON). P.M. acknowledges support from STFC research grant number ST/M001040/1. NCSa acknowledges funding by the European Union (ERC, FIERCE, 101052347). N.A.W. acknowledges UKSA grant ST/R004838/1.

PY - 2024/6

Y1 - 2024/6

N2 - Context. The TOI-421 planetary system contains two sub-Neptune-type planets (Pb ~ 5.2 days, Teq,b ~ 900 K, and Pc ~ 16.1 days, Teq,c ~ 650 K) and is a prime target to study the formation and evolution of planets and their atmospheres. The inner planet is especially interesting as the existence of a hydrogen-dominated atmosphere at its orbital separation cannot be explained by current formation models without previous orbital migration.Aims. We aim to improve the system parameters to further use them to model the interior structure and simulate the atmospheric evolution of both planets, to finally gain insights into their formation and evolution. We also investigate the possibility of detecting transit timing variations (TTVs).Methods. We jointly analysed photometric data of three TESS sectors and six CHEOPS visits as well as 156 radial velocity data points to retrieve improved planetary parameters. We also searched for TTVs and modelled the interior structure of the planets. Finally, we simulated the evolution of the primordial H-He atmospheres of the planets using two different modelling frameworks.Results. We determine the planetary radii and masses of TOI-421 b and c to be Rb = 2.64 ± 0.08 R⊕, Mb = 6.7 ± 0.6 M⊕, Rc = 5.09 ± 0.07 R⊕, and Mc = 14.1 ± 1.4 M⊕. Using these results we retrieved average planetary densities of ρb = 0.37 ± 0.05ρ⊕ and ρc = 0.107 ± 0.012 ρ⊕. We do not detect any statistically significant TTV signals. Assuming the presence of a hydrogen-dominated atmosphere, the interior structure modelling results in both planets having extensive envelopes. While the modelling of the atmospheric evolution predicts for TOI-421 b to have lost any primordial atmosphere that it could have accreted at its current orbital position, TOI-421 c could have started out with an initial atmospheric mass fraction somewhere between 10 and 35%.Conclusions. We conclude that the low observed mean density of TOI-421 b can only be explained by either a bias in the measured planetary parameters (e.g. driven by high-altitude clouds) and/or in the context of orbital migration. We also find that the results of atmospheric evolution models are strongly dependent on the employed planetary structure model.

AB - Context. The TOI-421 planetary system contains two sub-Neptune-type planets (Pb ~ 5.2 days, Teq,b ~ 900 K, and Pc ~ 16.1 days, Teq,c ~ 650 K) and is a prime target to study the formation and evolution of planets and their atmospheres. The inner planet is especially interesting as the existence of a hydrogen-dominated atmosphere at its orbital separation cannot be explained by current formation models without previous orbital migration.Aims. We aim to improve the system parameters to further use them to model the interior structure and simulate the atmospheric evolution of both planets, to finally gain insights into their formation and evolution. We also investigate the possibility of detecting transit timing variations (TTVs).Methods. We jointly analysed photometric data of three TESS sectors and six CHEOPS visits as well as 156 radial velocity data points to retrieve improved planetary parameters. We also searched for TTVs and modelled the interior structure of the planets. Finally, we simulated the evolution of the primordial H-He atmospheres of the planets using two different modelling frameworks.Results. We determine the planetary radii and masses of TOI-421 b and c to be Rb = 2.64 ± 0.08 R⊕, Mb = 6.7 ± 0.6 M⊕, Rc = 5.09 ± 0.07 R⊕, and Mc = 14.1 ± 1.4 M⊕. Using these results we retrieved average planetary densities of ρb = 0.37 ± 0.05ρ⊕ and ρc = 0.107 ± 0.012 ρ⊕. We do not detect any statistically significant TTV signals. Assuming the presence of a hydrogen-dominated atmosphere, the interior structure modelling results in both planets having extensive envelopes. While the modelling of the atmospheric evolution predicts for TOI-421 b to have lost any primordial atmosphere that it could have accreted at its current orbital position, TOI-421 c could have started out with an initial atmospheric mass fraction somewhere between 10 and 35%.Conclusions. We conclude that the low observed mean density of TOI-421 b can only be explained by either a bias in the measured planetary parameters (e.g. driven by high-altitude clouds) and/or in the context of orbital migration. We also find that the results of atmospheric evolution models are strongly dependent on the employed planetary structure model.

KW - Planets and satellites: composition

KW - Planets and satellites: fundamental parameters

KW - Planets and satellites: individual: TOI-421

U2 - 10.1051/0004-6361/202348584

DO - 10.1051/0004-6361/202348584

M3 - Article

SN - 0004-6361

VL - 686

JO - Astronomy & Astrophysics

JF - Astronomy & Astrophysics

M1 - A301

ER -

Characterisation of the TOI-421 planetary system using CHEOPS, TESS, and archival radial velocity data

Abstract

Keywords

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Projects

REVEAL: REVEALing Signatures of Habitable Worlds Hidden by Stellar Activity

AO2 - Professor Andrew Cameron: Project AO2 - Andrew Cameron

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

Datasets

TOI-421 light and velocity curves

Cite this