TOI-3686: A Hot Jupiter and Sub-Neptune In A 2:1 Mean-Motion Resonance
Abstract
Hot Jupiters are typically thought to be "lonely", but a small and growing subset of them have been found to have nearby planets in the same system. We present the discovery of a new member of this class of systems, TOI-3686. TOI-3686 c is a hot Jupiter with Porb = 5.078 days detected by NASA's TESS mission that shows peak-to-peak transit timing variations (TTVs) of 40 minutes, amongst the largest ever observed for a hot Jupiter. A subsequent search of the TESS data revealed the transits of a second planet, TOI-3686 b, a sub-Neptune with Porb = 2.54~days and peak-to-peak TTVs of 10 hours, ∼ 16% of its orbital period. We characterized the system through photodynamical modeling of photometry from TESS and ground-based facilities, as well as radial velocity measurements from the NEID and MAROON-X spectrographs. We find that the two planets in the TOI-3686 system are deep in a 2:1 mean-motion resonance, making this the only hot Jupiter system currently known to be in a truly resonant configuration, which may be related to its ≲1~Gyr system age. Systems like TOI-3686 likely formed through a dynamically quiescent pathway and were captured into resonance after migration through a disk, and may represent the high-mass end of processes that occur in compact systems of smaller planets.
Related
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- Numerical estimation of the capture ability of Neptunian mean motion resonances II. Influence of eccentricity and inclination
- Exploring the ultrahot Neptune LTT 9779 b with CRIRES+. Non-detection of helium transmission spectra and detection of H2O on the dayside
- Investigating potential causes for high inferred intrinsic temperatures of warm transiting Neptune and Sub-Neptune planets
BibTeX
@misc{yee2026toi3686,
title = {{TOI-3686: A Hot Jupiter and Sub-Neptune In A 2:1 Mean-Motion Resonance}},
author = {Samuel W. Yee and Tarisai Dziire and Karen A. Collins and Luke G. Bouma and Daniel Tamayo and Erik A. Petigura and Allyson Bieryla and David W. Latham and Samuel N. Quinn and Joshua N. Winn and Joel D. Hartman and Boris S. Safonov and Raquel Forés-Toribio and Jose A. Muñoz and Khalid Barkaoui and Richard P. Schwarz and Francis P. Wilkin and Paul Benni and Krzysztof Bernacki and Nikita Chazov and Eric G. Hintz and Glauk Hizmo and George Iwaszek and Adam Popowicz and Manfred Raetz and Miquel Serra-Ricart and Gregor Srdoc and Denise C. Stephens and Joseph Williams and Valerio Bozza and Otabek Burkhonov and Roger Dymock and Salokhiddin Sh. Ergashev and Karen Fischer and Cristilyn N. Gardner-Watkins and Ferran Grau Horta and Adam Lark and Katherine Linnenkohl and Ken Mason and Edward J. Michaels and Owen A. J. Mitchem and Seth M. Pritchard and Lauren A. Sgro and Neil B. Thomas and Siegfried Vanaverbeke and Pieter Vuylsteke and Jeroen Audenaert and Keith Horne and Felipe Murgas and Emma Nabbie and Enric Palle and Ramotholo Sefako and Avi Shporer},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.28533},
eprint = {2610.28533},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.28533},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - TOI-3686: A Hot Jupiter and Sub-Neptune In A 2:1 Mean-Motion Resonance
AU - Samuel W. Yee
AU - Tarisai Dziire
AU - Karen A. Collins
AU - Luke G. Bouma
AU - Daniel Tamayo
AU - Erik A. Petigura
AU - Allyson Bieryla
AU - David W. Latham
AU - Samuel N. Quinn
AU - Joshua N. Winn
AU - Joel D. Hartman
AU - Boris S. Safonov
AU - Raquel Forés-Toribio
AU - Jose A. Muñoz
AU - Khalid Barkaoui
AU - Richard P. Schwarz
AU - Francis P. Wilkin
AU - Paul Benni
AU - Krzysztof Bernacki
AU - Nikita Chazov
AU - Eric G. Hintz
AU - Glauk Hizmo
AU - George Iwaszek
AU - Adam Popowicz
AU - Manfred Raetz
AU - Miquel Serra-Ricart
AU - Gregor Srdoc
AU - Denise C. Stephens
AU - Joseph Williams
AU - Valerio Bozza
AU - Otabek Burkhonov
AU - Roger Dymock
AU - Salokhiddin Sh. Ergashev
AU - Karen Fischer
AU - Cristilyn N. Gardner-Watkins
AU - Ferran Grau Horta
AU - Adam Lark
AU - Katherine Linnenkohl
AU - Ken Mason
AU - Edward J. Michaels
AU - Owen A. J. Mitchem
AU - Seth M. Pritchard
AU - Lauren A. Sgro
AU - Neil B. Thomas
AU - Siegfried Vanaverbeke
AU - Pieter Vuylsteke
AU - Jeroen Audenaert
AU - Keith Horne
AU - Felipe Murgas
AU - Emma Nabbie
AU - Enric Palle
AU - Ramotholo Sefako
AU - Avi Shporer
PY - 2026
DA - 2026/10/20
PB - arXiv
DO - 10.48550/arxiv.2610.28533
UR - https://arxiv.org/abs/2610.28533
AB - Hot Jupiters are typically thought to be "lonely", but a small and growing subset of them have been found to have nearby planets in the same system. We present the discovery of a new member of this class of systems, TOI-3686. TOI-3686 c is a hot Jupiter with P_orb = 5.078 days detected by NASA's TESS mission that shows peak-to-peak transit timing variations (TTVs) of 40 minutes, amongst the largest ever observed for a hot Jupiter. A subsequent search of the TESS data revealed the transits of a second planet, TOI-3686 b, a sub-Neptune with P_orb = 2.54~days and peak-to-peak TTVs of 10 hours, ∼ 16% of its orbital period. We characterized the system through photodynamical modeling of photometry from TESS and ground-based facilities, as well as radial velocity measurements from the NEID and MAROON-X spectrographs. We find that the two planets in the TOI-3686 system are deep in a 2:1 mean-motion resonance, making this the only hot Jupiter system currently known to be in a truly resonant configuration, which may be related to its ≲1~Gyr system age. Systems like TOI-3686 likely formed through a dynamically quiescent pathway and were captured into resonance after migration through a disk, and may represent the high-mass end of processes that occur in compact systems of smaller planets.
ER -