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

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

Abstract

Context. The discovery and characterization of mini Neptunes has a crucial impact on planetary formation and evolution theories. A precise
characterization of their orbital parameters and atmospheric properties would give us valuable hints to improve our 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 can estimate 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 finally assume different atmospheric compositions and define possible atmospheric characterization 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 revealed significant transit timing variations (TTV) with an amplitude of ∼ 10 min and ∼ 40 min, respectively, for planet -b and -c. With the masses computed from the radial velocities data set, we obtained a density of (0.39±0.10) ρ_⊕ and (0.076±0.038) ρ_⊕ for planet -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 kept its primary atmosphere or not, constraining 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 Neptune known so far, and it is of
great interest among the scientific community since it could constrain our formation scenarios. JWST observations could give us valuable insights
to characterise this interesting system.

Original language	English
Journal	Astronomy & Astrophysics
Volume	Forthcoming article
DOIs	https://doi.org/10.1051/0004-6361/202451180
Publication status	Accepted/In press - 6 Dec 2024

Access to Document

10.1051/0004-6361/202451180

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

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. (Accepted/In press). A joint effort to discover and characterize two resonant mini Neptunes around TOI-1803 with TESS, HARPS-N and CHEOPS. Astronomy & Astrophysics, Forthcoming article. 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 has a crucial impact on planetary formation and evolution theories. A precisecharacterization of their orbital parameters and atmospheric properties would give us valuable hints to improve our 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 can estimate the radius and the mass of both planets. We used a multidimensionalGaussian Process with a quasi-periodic kernel to disentangle the planetary components from the stellar activity in the HARPS-N dataset. Weperformed dynamical modeling to explain the orbital configuration and performed planetary formation and evolution simulations. For the leastdense planet, we finally assume different atmospheric compositions and define possible atmospheric characterization scenarios with simulatedJWST 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 revealed significant transit timing variations (TTV) with an amplitude of ∼ 10 min and ∼ 40 min, respectively, for planet -b and -c. With the masses computed from the radial velocities data set, we obtained a density of (0.39±0.10) ρ⊕ and (0.076±0.038) ρ⊕ for planet -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 understandwhether the planet kept its primary atmosphere or not, constraining 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-basedphotometry opens scenarios for a more precise mass determination. TOI-1803 c is one of the least dense mini Neptune known so far, and it is ofgreat interest among the scientific community since it could constrain our formation scenarios. JWST observations could give us valuable insightsto characterise this interesting system.",

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: . ACC acknowledges support from STFC consolidated grant number ST/V000861/1, and UKSA grant number ST/X002217/1. DT acknowledges the support from the European Research Council via the Horizon 2020 Framework Programme ERC Synergy “ECOGAL” Project GA-855130. CHe acknowledges support from the European Union H2020-MSCA-ITN-2019 under Grant Agreement no. 860470 (CHAMELEON). PM acknowledges support from STFC research grant number ST/R000638/1. NCSa acknowledges funding by the European Union (ERC, FIERCE, 10105234). NAW acknowledges UKSA grant ST/R004838/1. TWi acknowledges support from the UKSA and the University of Warwick Co-funded by the European Union (ERC, FIERCE, 101052347). ",

year = "2024",

month = dec,

day = "6",

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

language = "English",

volume = "Forthcoming article",

journal = "Astronomy & Astrophysics",

issn = "0004-6361",

publisher = "EDP SCIENCES S A",

}

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 2024, 'A joint effort to discover and characterize two resonant mini Neptunes around TOI-1803 with TESS, HARPS-N and CHEOPS', Astronomy & Astrophysics, vol. Forthcoming article. 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.

AU - Mantovan, G.

AU - Nardiello, D.

AU - Nascimbeni, V.

AU - Lanza, A. F.

AU - Bekkelien, A.

AU - Sozzetti, A.

AU - Broeg, C.

AU - Naponiello, L.

AU - Lendl, M.

AU - Bonomo, A. S.

AU - Simon, A. E.

AU - Desidera, S.

AU - Piotto, G.

AU - Mancini, L.

AU - Hooton, M. J.

AU - Bignamini, A.

AU - Egger, J. A.

AU - Maggio, A.

AU - Alibert, Y.

AU - Locci, D.

AU - Delrez, L.

AU - Biassoni, F.

AU - Fossati, L.

AU - Cabona, L.

AU - Lacedelli, G.

AU - Carleo, I.

AU - Leonardi, P.

AU - Andreuzzi, G.

AU - Brandeker, A.

AU - Cosentino, R.

AU - Correia, A. C. M.

AU - Claudi, R.

AU - Alonso, R.

AU - Damasso, M.

AU - Wilson, T. G.

AU - Bàrczy, T.

AU - Pinamonti, M.

AU - Baker, D.

AU - Barkaoui, K.

AU - Barrado Navascues, D.

AU - Barros, S. C. C.

AU - Baumjohann, W.

AU - Beck, T.

AU - Beichman, C.

AU - Benz, W.

AU - Bieryla, A.

AU - Billot, N.

AU - Bosch-Cabot, P.

AU - Bouma, L. G.

AU - Ciardi, D. R.

AU - Cameron, A. Collier

AU - Collins, K. A.

AU - Crossfield, Ian J. M.

AU - Csizmadia, Sz

AU - Cubillos, P. E.

AU - Davies, M. B.

AU - Deleuil, M.

AU - Deline, A.

AU - Demangeon, O. D. S.

AU - Demory, B. -O.

AU - Derekas, A.

AU - Dragomir, D.

AU - Edwards, B.

AU - Ehrenreich, D.

AU - Erikson, A.

AU - Falk, B.

AU - Fortier, A.

AU - Fridlund, M.

AU - Fukui, A.

AU - Gandolfi, D.

AU - Gazeas, K.

AU - Gillon, M.

AU - Gonzales, E.

AU - Gudel, M.

AU - Guerra, P.

AU - Günther, M. N.

AU - Heitzmann, A.

AU - Helling, Ch

AU - Howell, S. B.

AU - Isaak, K. G.

AU - Jenkins, J.

AU - Kiss, L. L.

AU - Korth, J.

AU - Lam, K. W. F.

AU - Laskar, J.

AU - Lecavelier des Etangs, A.

AU - Magrin, D.

AU - Matson, R.

AU - Matthews, E. C.

AU - Maxted, P. F. L.

AU - McDermott, S.

AU - Munari, M.

AU - Mordasini, C.

AU - Narita, N.

AU - Olofsson, G.

AU - Ottensamer, R.

AU - Pagano, I.

AU - Pallè, E.

AU - Peter, G.

AU - Pollacco, D.

AU - Queloz, D.

AU - Ragazzoni, R.

AU - Rando, N.

AU - Ratti, F.

AU - Rauer, H.

AU - Ribas, I.

AU - Salmon, S.

AU - Santos, N. C.

AU - Scandariato, G.

AU - Seager, S.

AU - Sègransan, D.

AU - Smith, A. M. S.

AU - Schlieder, J.

AU - Schwarz, R. P.

AU - Shporer, A.

AU - Sousa, S. G.

AU - Stalport, M.

AU - Steinberger, M.

AU - Sulis, S.

AU - Szabò, Gy M.

AU - Twicken, J. D.

AU - Udry, S.

AU - Van Grootel, V.

AU - Venturini, J.

AU - Villaver, E.

AU - Walton, N. A.

AU - Winn, J. N.

N1 - Funding: . ACC acknowledges support from STFC consolidated grant number ST/V000861/1, and UKSA grant number ST/X002217/1. DT acknowledges the support from the European Research Council via the Horizon 2020 Framework Programme ERC Synergy “ECOGAL” Project GA-855130. CHe acknowledges support from the European Union H2020-MSCA-ITN-2019 under Grant Agreement no. 860470 (CHAMELEON). PM acknowledges support from STFC research grant number ST/R000638/1. NCSa acknowledges funding by the European Union (ERC, FIERCE, 10105234). NAW acknowledges UKSA grant ST/R004838/1. TWi acknowledges support from the UKSA and the University of Warwick Co-funded by the European Union (ERC, FIERCE, 101052347).

PY - 2024/12/6

Y1 - 2024/12/6

N2 - Context. The discovery and characterization of mini Neptunes has a crucial impact on planetary formation and evolution theories. A precisecharacterization of their orbital parameters and atmospheric properties would give us valuable hints to improve our 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 can estimate the radius and the mass of both planets. We used a multidimensionalGaussian Process with a quasi-periodic kernel to disentangle the planetary components from the stellar activity in the HARPS-N dataset. Weperformed dynamical modeling to explain the orbital configuration and performed planetary formation and evolution simulations. For the leastdense planet, we finally assume different atmospheric compositions and define possible atmospheric characterization scenarios with simulatedJWST 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 revealed significant transit timing variations (TTV) with an amplitude of ∼ 10 min and ∼ 40 min, respectively, for planet -b and -c. With the masses computed from the radial velocities data set, we obtained a density of (0.39±0.10) ρ⊕ and (0.076±0.038) ρ⊕ for planet -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 understandwhether the planet kept its primary atmosphere or not, constraining 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-basedphotometry opens scenarios for a more precise mass determination. TOI-1803 c is one of the least dense mini Neptune known so far, and it is ofgreat interest among the scientific community since it could constrain our formation scenarios. JWST observations could give us valuable insightsto characterise this interesting system.

AB - Context. The discovery and characterization of mini Neptunes has a crucial impact on planetary formation and evolution theories. A precisecharacterization of their orbital parameters and atmospheric properties would give us valuable hints to improve our 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 can estimate the radius and the mass of both planets. We used a multidimensionalGaussian Process with a quasi-periodic kernel to disentangle the planetary components from the stellar activity in the HARPS-N dataset. Weperformed dynamical modeling to explain the orbital configuration and performed planetary formation and evolution simulations. For the leastdense planet, we finally assume different atmospheric compositions and define possible atmospheric characterization scenarios with simulatedJWST 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 revealed significant transit timing variations (TTV) with an amplitude of ∼ 10 min and ∼ 40 min, respectively, for planet -b and -c. With the masses computed from the radial velocities data set, we obtained a density of (0.39±0.10) ρ⊕ and (0.076±0.038) ρ⊕ for planet -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 understandwhether the planet kept its primary atmosphere or not, constraining 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-basedphotometry opens scenarios for a more precise mass determination. TOI-1803 c is one of the least dense mini Neptune known so far, and it is ofgreat interest among the scientific community since it could constrain our formation scenarios. JWST observations could give us valuable insightsto characterise this interesting system.

U2 - 10.1051/0004-6361/202451180

DO - 10.1051/0004-6361/202451180

M3 - Article

SN - 0004-6361

VL - Forthcoming article

JO - Astronomy & Astrophysics

JF - Astronomy & Astrophysics

ER -

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

Abstract

Access to Document

Fingerprint

Projects

AO2 - Professor Andrew Cameron: Project AO2 - Andrew Cameron

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

Cite this