Hints of a close outer companion to the ultra-hot Jupiter TOI-2109 b?

J. -V. Harre; A. M. S. Smith; S. C. C. Barros; V. Singh; J. Korth; A. Brandeker; A. Collier Cameron; M. Lendl; T. G. Wilson; L. Borsato; Sz Csizmadia; J. Cabrera; H. Parviainen; A. C. M. Correia; B. Akinsanmi; N. Rosario; P. Leonardi; L. M. Serrano; Y. Alibert; R. Alonso; J. Asquier; T. Bárczy; D. Barrado Navascues; W. Baumjohann; W. Benz; N. Billot; C. Broeg; M. -D. Busch; P. E. Cubillos; M. B. Davies; M. Deleuil; A. Deline; L. Delrez; O. D. S. Demangeon; B. -O. Demory; A. Derekas; B. Edwards; D. Ehrenreich; A. Erikson; A. Fortier; L. Fossati; M. Fridlund; D. Gandolfi; K. Gazeas; M. Gillon; M. Güdel; M. N. Günther; A. Heitzmann; Ch Helling; K. G. Isaak; L. L. Kiss; K. W. F. Lam; J. Laskar; A. Lecavelier des Etangs; D. Magrin; P. F. L. Maxted; B. Merín; C. Mordasini; V. Nascimbeni; G. Olofsson; R. Ottensamer; I. Pagano; E. Pallé; G. Peter; D. Piazza; G. Piotto; D. Pollacco; D. Queloz; R. Ragazzoni; N. Rando; H. Rauer; I. Ribas; N. C. Santos; G. Scandariato; D. Ségransan; A. E. Simon; S. G. Sousa; M. Stalport; S. Sulis; Gy M. Szabó; S. Udry; B. Ulmer; V. Van Grootel; J. Venturini; E. Villaver; V. Viotto; N. A. Walton; R. West; K. Westerdorff

doi:10.1051/0004-6361/202451068

Hints of a close outer companion to the ultra-hot Jupiter TOI-2109 b?

J. -V. Harre, A. M. S. Smith, S. C. C. Barros, V. Singh, J. Korth, A. Brandeker, A. Collier Cameron, M. Lendl, T. G. Wilson, L. Borsato, Sz Csizmadia, J. Cabrera, H. Parviainen, A. C. M. Correia, B. Akinsanmi, N. Rosario, P. Leonardi, L. M. Serrano, Y. Alibert, R. AlonsoJ. Asquier, T. Bárczy, D. Barrado Navascues, W. Baumjohann, W. Benz, N. Billot, C. Broeg, M. -D. Busch, P. E. Cubillos, M. B. Davies, M. Deleuil, A. Deline, L. Delrez, O. D. S. Demangeon, B. -O. Demory, A. Derekas, B. Edwards, D. Ehrenreich, A. Erikson, A. Fortier, L. Fossati, M. Fridlund, D. Gandolfi, K. Gazeas, M. Gillon, M. Güdel, M. N. Günther, A. Heitzmann, Ch Helling, K. G. Isaak, L. L. Kiss, K. W. F. Lam, J. Laskar, A. Lecavelier des Etangs, D. Magrin, P. F. L. Maxted, B. Merín, C. Mordasini, V. Nascimbeni, G. Olofsson, R. Ottensamer, I. Pagano, E. Pallé, G. Peter, D. Piazza, G. Piotto, D. Pollacco, D. Queloz, R. Ragazzoni, N. Rando, H. Rauer, I. Ribas, N. C. Santos, G. Scandariato, D. Ségransan, A. E. Simon, S. G. Sousa, M. Stalport, S. Sulis, Gy M. Szabó, S. Udry, B. Ulmer, V. Van Grootel, J. Venturini, E. Villaver, V. Viotto, N. A. Walton, R. West, K. Westerdorff

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

Abstract

Context. Hot Jupiters (HJs) with close-by planetary companions are rare, with only a handful of them having been discovered so far. This could be due to their suggested dynamical histories, which lead to the possible ejection of other planets. TOI-2109 b is special in this regard because it is the HJ with the closest relative separation from its host star, being separated by less than 2.3 stellar radii. Unexpectedly, transit timing measurements from recently obtained CHEOPS observations show low-amplitude transit-timing variations (TTVs).

Aims. We aim to search for signs of orbital decay and to characterise the apparent TTVs in an attempt to gain information about a possible companion.

Methods. We fitted the newly obtained CHEOPS light curves using TLCM and extracted the resulting mid-transit timings. Successively, we used these measurements in combination with TESS and archival photometric data and radial velocity (RV) data to estimate the rate of tidal orbital decay of TOI-2109 b, and also to characterise the TTVs using the N-body code TRADES and the photo-dynamical approach of PyTTV.

Results. We find tentative evidence at 3σ for orbital decay in the TOI-2109 system when we correct the mid-transit timings using the best-fitting sinusoidal model of the TTVs. We do not detect additional transits in the available photometric data, but find evidence supporting the authenticity of the apparent TTVs, indicating a close-by, outer companion with P_c > 1.125 d. Due to the fast rotation of the star, the new planetary candidate cannot be detected in the available RV measurements, and its parameters can only be loosely constrained by our joint TTV and RV modelling.

Conclusions. TOI-2109 could join a small group of rare HJ systems that host close-by planetary companions, only one of which (WASP-47 b) has an outer companion. More high-precision photometric measurements are necessary to confirm the existence of this planetary companion.

Original language	English
Article number	A254
Number of pages	21
Journal	Astronomy & Astrophysics
Volume	692
Early online date	17 Dec 2024
DOIs	https://doi.org/10.1051/0004-6361/202451068
Publication status	Published - Dec 2024

Keywords

Methods: data analysis
Techniques: photometricq
Planets and satellites: dynamical evolution and stability
Planets and satellites: gaseous planets
Planet-star interactions

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1 Active
2 Finished

PLATO 22-25: Support for the PLATO Development Phase 2022-2025: Planet candidate ranking and validation
Cameron, A. C. (PI)
Science & Technology Facilities Council
1/04/22 → 31/03/25
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

Hints of a close outer companion to the ultra-hot Jupiter TOI-2109 b? (dataset)
Cameron, A. C. (Creator), VizieR On-line Data Catalog, 2024
Dataset

Cite this

Harre, J. .-V., Smith, A. M. S., Barros, S. C. C., Singh, V., Korth, J., Brandeker, A., Cameron, A. C., Lendl, M., Wilson, T. G., Borsato, L., Csizmadia, S., Cabrera, J., Parviainen, H., Correia, A. C. M., Akinsanmi, B., Rosario, N., Leonardi, P., Serrano, L. M., Alibert, Y., ... Westerdorff, K. (2024). Hints of a close outer companion to the ultra-hot Jupiter TOI-2109 b? Astronomy & Astrophysics, 692, Article A254. https://doi.org/10.1051/0004-6361/202451068

@article{1f96c5017675452fb93b1df84afeca72,

title = "Hints of a close outer companion to the ultra-hot Jupiter TOI-2109 b?",

abstract = "Context. Hot Jupiters (HJs) with close-by planetary companions are rare, with only a handful of them having been discovered so far. This could be due to their suggested dynamical histories, which lead to the possible ejection of other planets. TOI-2109 b is special in this regard because it is the HJ with the closest relative separation from its host star, being separated by less than 2.3 stellar radii. Unexpectedly, transit timing measurements from recently obtained CHEOPS observations show low-amplitude transit-timing variations (TTVs). Aims. We aim to search for signs of orbital decay and to characterise the apparent TTVs in an attempt to gain information about a possible companion. Methods. We fitted the newly obtained CHEOPS light curves using TLCM and extracted the resulting mid-transit timings. Successively, we used these measurements in combination with TESS and archival photometric data and radial velocity (RV) data to estimate the rate of tidal orbital decay of TOI-2109 b, and also to characterise the TTVs using the N-body code TRADES and the photo-dynamical approach of PyTTV. Results. We find tentative evidence at 3σ for orbital decay in the TOI-2109 system when we correct the mid-transit timings using the best-fitting sinusoidal model of the TTVs. We do not detect additional transits in the available photometric data, but find evidence supporting the authenticity of the apparent TTVs, indicating a close-by, outer companion with Pc > 1.125 d. Due to the fast rotation of the star, the new planetary candidate cannot be detected in the available RV measurements, and its parameters can only be loosely constrained by our joint TTV and RV modelling. Conclusions. TOI-2109 could join a small group of rare HJ systems that host close-by planetary companions, only one of which (WASP-47 b) has an outer companion. More high-precision photometric measurements are necessary to confirm the existence of this planetary companion.",

keywords = "Methods: data analysis, Techniques: photometricq, Planets and satellites: dynamical evolution and stability, Planets and satellites: gaseous planets, Planet-star interactions",

author = "Harre, {J. -V.} and Smith, {A. M. S.} and Barros, {S. C. C.} and V. Singh and J. Korth and A. Brandeker and Cameron, {A. Collier} and M. Lendl and Wilson, {T. G.} and L. Borsato and Sz Csizmadia and J. Cabrera and H. Parviainen and Correia, {A. C. M.} and B. Akinsanmi and N. Rosario and P. Leonardi and Serrano, {L. M.} and Y. Alibert and R. Alonso and J. Asquier and T. B{\'a}rczy and {Barrado Navascues}, D. and W. Baumjohann and W. Benz and N. Billot and C. Broeg and Busch, {M. -D.} and Cubillos, {P. E.} and Davies, {M. B.} and M. Deleuil and A. Deline and L. Delrez and Demangeon, {O. D. S.} and Demory, {B. -O.} and A. Derekas and B. Edwards and D. Ehrenreich and A. Erikson and A. Fortier and L. Fossati and M. Fridlund and D. Gandolfi and K. Gazeas and M. Gillon and M. G{\"u}del and G{\"u}nther, {M. N.} and A. Heitzmann and Ch Helling and Isaak, {K. G.} and Kiss, {L. L.} and Lam, {K. W. F.} and J. Laskar and {Lecavelier des Etangs}, A. and D. Magrin and Maxted, {P. F. L.} and B. Mer{\'i}n and C. Mordasini and V. Nascimbeni and G. Olofsson and R. Ottensamer and I. Pagano and E. Pall{\'e} and G. Peter and D. Piazza and G. Piotto and D. Pollacco and D. Queloz and R. Ragazzoni and N. Rando and H. Rauer and I. Ribas and Santos, {N. C.} and G. Scandariato and D. S{\'e}gransan and Simon, {A. E.} and Sousa, {S. G.} and M. Stalport and S. Sulis and Szab{\'o}, {Gy M.} and S. Udry and B. Ulmer and {Van Grootel}, V. and J. Venturini and E. Villaver and V. Viotto and Walton, {N. A.} and R. West and K. Westerdorff",

note = "Funding: ACC acknowledges support from STFC consolidated grant number ST/V000861/1, and UKSA grant number ST/X002217/1. 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, 101052347). NAW acknowledges UKSA grant ST/R004838/1.",

year = "2024",

month = dec,

doi = "10.1051/0004-6361/202451068",

language = "English",

volume = "692",

journal = "Astronomy & Astrophysics",

issn = "0004-6361",

publisher = "EDP SCIENCES S A",

}

Harre, J-V, Smith, AMS, Barros, SCC, Singh, V, Korth, J, Brandeker, A, Cameron, AC, Lendl, M, Wilson, TG, Borsato, L, Csizmadia, S, Cabrera, J, Parviainen, H, Correia, ACM, Akinsanmi, B, Rosario, N, Leonardi, P, Serrano, LM, Alibert, Y, Alonso, R, Asquier, J, Bárczy, T, Barrado Navascues, D, Baumjohann, W, Benz, W, Billot, N, Broeg, C, Busch, M-D, Cubillos, PE, Davies, MB, Deleuil, M, Deline, A, Delrez, L, Demangeon, ODS, Demory, B-O, Derekas, A, Edwards, B, Ehrenreich, D, Erikson, A, Fortier, A, Fossati, L, Fridlund, M, Gandolfi, D, Gazeas, K, Gillon, M, Güdel, M, Günther, MN, Heitzmann, A, Helling, C, Isaak, KG, Kiss, LL, Lam, KWF, Laskar, J, Lecavelier des Etangs, A, Magrin, D, Maxted, PFL, Merín, B, Mordasini, C, Nascimbeni, V, Olofsson, G, Ottensamer, R, Pagano, I, Pallé, E, Peter, G, Piazza, D, Piotto, G, Pollacco, D, Queloz, D, Ragazzoni, R, Rando, N, Rauer, H, Ribas, I, Santos, NC, Scandariato, G, Ségransan, D, Simon, AE, Sousa, SG, Stalport, M, Sulis, S, Szabó, GM, Udry, S, Ulmer, B, Van Grootel, V, Venturini, J, Villaver, E, Viotto, V, Walton, NA, West, R & Westerdorff, K 2024, 'Hints of a close outer companion to the ultra-hot Jupiter TOI-2109 b?', Astronomy & Astrophysics, vol. 692, A254. https://doi.org/10.1051/0004-6361/202451068