A Warm Massive Pair of Planets around TOI-1232 Revealed with Transit-timing Variations and Doppler Spectroscopy

Deyan P. Mihaylov; Jan Eberhardt; Trifon Trifonov; Rafael Brahm; Thomas Henning; Andrés Jordán; Denitza Stoeva; Matías I. Jones; Lorena Acuña-Aguirre; Stefan Stefanov; M. Tala Pinto; Melissa J. Hobson; Nestor Espinoza; Felipe I. Rojas; Martin Schlecker; Vladimir Bozhilov; Tristan Guillot; Amaury H. M. J. Triaud; Jack J. Lissauer; Judith Korth; Hannu Parviainen; Laura Kreidberg; Philippe Bendjoya; Olga Suarez; Carl Ziegler; Pamela Rowden; Alexander Rudat; Veselin Kostov; Joshua N. Winn; Jon M. Jenkins; Karen A. Collins; Cristilyn N. Watkins; Don J. Radford; Chris Stockdale; Tianjun Gan

doi:10.3847/1538-3881/ae2312

A Warm Massive Pair of Planets around TOI-1232 Revealed with Transit-timing Variations and Doppler Spectroscopy

Deyan P. Mihaylov^*
, Jan Eberhardt
, Trifon Trifonov
, Rafael Brahm
, Thomas Henning
, Andrés Jordán
, Denitza Stoeva
, Matías I. Jones
, Lorena Acuña-Aguirre
, Stefan Stefanov
, M. Tala Pinto
, Melissa J. Hobson
, Nestor Espinoza
, Felipe I. Rojas
, Martin Schlecker
, Vladimir Bozhilov
, Tristan Guillot
, Amaury H. M. J. Triaud
, Jack J. Lissauer
, Judith Korth

Hannu Parviainen, Laura Kreidberg, Philippe Bendjoya, Olga Suarez, Carl Ziegler, Pamela Rowden, Alexander Rudat, Veselin Kostov, Joshua N. Winn, Jon M. Jenkins, Karen A. Collins, Cristilyn N. Watkins, Don J. Radford, Chris Stockdale, Tianjun Gan

^*Corresponding author for this work

Physics and Astronomy

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

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Abstract

TOI-1232 is a G dwarf star with a mass of 1.06_−0.06^+0.07M_⊙ , a radius of 1.07 ± 0.05 R_⊙, and a slightly higher metallicity than solar of Fe/H = 0.18 ± 0.05. The star hosts a transiting warm Jovian-mass planet, TOI-1232 b, with an orbital period of P_b = 14.256_−0.001^+0.001 days, identified with data from multiple sectors of the TESS space telescope. The TESS light curve of TOI-1232 is complex, as it is contaminated by a background eclipsing binary with a period of 1.37 days. TOI-1232 b was firmly confirmed by ground-based transit follow-up campaigns from the Las Cumbres, Hazelwood, Brierfield, and ASTEP observatories. Additionally, the TESS transits of TOI-1232 b exhibit strong transit-timing variations (TTVs) with a superperiod of 235.5 ± 0.7 days and a semiamplitude of 27 minutes. Radial velocity (RV) follow-up with the FEROS spectrograph confirms the planetary nature of the transiting candidate, while a self-consistent N-body analysis of RVs and TTVs pinpoints the presence of a second outer Saturn-mass companion, TOI-1232 c with a period of P_c = 30.356_−0.012^+0.010 days. The TOI-1232 warm-giant system is particularly important due to the evidence of two massive planets that reside near the 2:1 commensurability but are not locked in a mean-motion resonance. Thanks to TESS, we have revealed a handful of these rare systems. Hence, TOI-1232 is an important addition to understanding the formation and dynamical evolution of such compact, massive, warm giant planets.

Original language	English
Article number	173
Number of pages	28
Journal	The Astronomical Journal
Volume	171
Issue number	3
Early online date	20 Feb 2026
DOIs	https://doi.org/10.3847/1538-3881/ae2312
Publication status	Published - 2 Mar 2026

Bibliographical note

Based on observations collected at the European Organization for Astronomical Research in the Southern Hemisphere under MPG programmes 0102.A-9006, 0103.A-9008, 0104.A-9007

Keywords

Transit timing variation method
Radial velocity
Transit photometry
Exoplanet dynamics

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10.3847/1538-3881/ae2312Licence: Creative Commons: Attribution (CC BY)

MihaylovDP2026WarmFinal published version, 25 MBLicence: Creative Commons: Attribution (CC BY)

1 Active
3 Finished

Temperate planets from Chile & Antarctica
Triaud, A. (Principal Investigator)
SCIENCE & TECHNOLOGY FACILITIES COUNCIL
1/04/24 → 31/03/27
Project: Research
An upgrade to the mount of the ASTEP telescope
Vecchio, A. (Co-Investigator), Triaud, A. (Principal Investigator), Nicholl, M. (Co-Investigator) & Schmidt, P. (Co-Investigator)
SCIENCE & TECHNOLOGY FACILITIES COUNCIL
1/07/21 → 31/12/21
Project: Research Councils
H2020_ERC_BEBOP
Triaud, A. (Principal Investigator)
European Commission
1/11/18 → 31/10/24
Project: EU
Red-Enhanced Cameras to Seek Rocky Planets Transiting Ultra-Cool Dwarfs
Chaplin, B. (Co-Investigator) & Triaud, A. (Principal Investigator)
SCIENCE & TECHNOLOGY FACILITIES COUNCIL
1/10/18 → 20/09/19
Project: Research Councils

Cite this

Mihaylov, D. P., Eberhardt, J., Trifonov, T., Brahm, R., Henning, T., Jordán, A., Stoeva, D., Jones, M. I., Acuña-Aguirre, L., Stefanov, S., Tala Pinto, M., Hobson, M. J., Espinoza, N., Rojas, F. I., Schlecker, M., Bozhilov, V., Guillot, T., Triaud, A. H. M. J., Lissauer, J. J., ... Gan, T. (2026). A Warm Massive Pair of Planets around TOI-1232 Revealed with Transit-timing Variations and Doppler Spectroscopy. The Astronomical Journal, 171(3), Article 173. https://doi.org/10.3847/1538-3881/ae2312

@article{19008d879c7c432d8812622f373866a6,

title = "A Warm Massive Pair of Planets around TOI-1232 Revealed with Transit-timing Variations and Doppler Spectroscopy",

abstract = "TOI-1232 is a G dwarf star with a mass of 1.06−0.06+0.07M⊙ , a radius of 1.07 ± 0.05 R⊙, and a slightly higher metallicity than solar of Fe/H = 0.18 ± 0.05. The star hosts a transiting warm Jovian-mass planet, TOI-1232 b, with an orbital period of Pb = 14.256−0.001+0.001 days, identified with data from multiple sectors of the TESS space telescope. The TESS light curve of TOI-1232 is complex, as it is contaminated by a background eclipsing binary with a period of 1.37 days. TOI-1232 b was firmly confirmed by ground-based transit follow-up campaigns from the Las Cumbres, Hazelwood, Brierfield, and ASTEP observatories. Additionally, the TESS transits of TOI-1232 b exhibit strong transit-timing variations (TTVs) with a superperiod of 235.5 ± 0.7 days and a semiamplitude of 27 minutes. Radial velocity (RV) follow-up with the FEROS spectrograph confirms the planetary nature of the transiting candidate, while a self-consistent N-body analysis of RVs and TTVs pinpoints the presence of a second outer Saturn-mass companion, TOI-1232 c with a period of Pc = 30.356−0.012+0.010 days. The TOI-1232 warm-giant system is particularly important due to the evidence of two massive planets that reside near the 2:1 commensurability but are not locked in a mean-motion resonance. Thanks to TESS, we have revealed a handful of these rare systems. Hence, TOI-1232 is an important addition to understanding the formation and dynamical evolution of such compact, massive, warm giant planets.",

keywords = "Transit timing variation method, Radial velocity, Transit photometry, Exoplanet dynamics",

author = "Mihaylov, \{Deyan P.\} and Jan Eberhardt and Trifon Trifonov and Rafael Brahm and Thomas Henning and Andr{\'e}s Jord{\'a}n and Denitza Stoeva and Jones, \{Mat{\'i}as I.\} and Lorena Acu{\~n}a-Aguirre and Stefan Stefanov and \{Tala Pinto\}, M. and Hobson, \{Melissa J.\} and Nestor Espinoza and Rojas, \{Felipe I.\} and Martin Schlecker and Vladimir Bozhilov and Tristan Guillot and Triaud, \{Amaury H. M. J.\} and Lissauer, \{Jack J.\} and Judith Korth and Hannu Parviainen and Laura Kreidberg and Philippe Bendjoya and Olga Suarez and Carl Ziegler and Pamela Rowden and Alexander Rudat and Veselin Kostov and Winn, \{Joshua N.\} and Jenkins, \{Jon M.\} and Collins, \{Karen A.\} and Watkins, \{Cristilyn N.\} and Radford, \{Don J.\} and Chris Stockdale and Tianjun Gan",

note = "Based on observations collected at the European Organization for Astronomical Research in the Southern Hemisphere under MPG programmes 0102.A-9006, 0103.A-9008, 0104.A-9007",

year = "2026",

month = mar,

day = "2",

doi = "10.3847/1538-3881/ae2312",

language = "English",

volume = "171",

journal = "The Astronomical Journal",

issn = "0004-6256",

publisher = "American Astronomical Society",

number = "3",

}

Mihaylov, DP, Eberhardt, J, Trifonov, T, Brahm, R, Henning, T, Jordán, A, Stoeva, D, Jones, MI, Acuña-Aguirre, L, Stefanov, S, Tala Pinto, M, Hobson, MJ, Espinoza, N, Rojas, FI, Schlecker, M, Bozhilov, V, Guillot, T, Triaud, AHMJ, Lissauer, JJ, Korth, J, Parviainen, H, Kreidberg, L, Bendjoya, P, Suarez, O, Ziegler, C, Rowden, P, Rudat, A, Kostov, V, Winn, JN, Jenkins, JM, Collins, KA, Watkins, CN, Radford, DJ, Stockdale, C & Gan, T 2026, 'A Warm Massive Pair of Planets around TOI-1232 Revealed with Transit-timing Variations and Doppler Spectroscopy', The Astronomical Journal, vol. 171, no. 3, 173. https://doi.org/10.3847/1538-3881/ae2312

TY - JOUR

T1 - A Warm Massive Pair of Planets around TOI-1232 Revealed with Transit-timing Variations and Doppler Spectroscopy

AU - Mihaylov, Deyan P.

AU - Eberhardt, Jan

AU - Trifonov, Trifon

AU - Brahm, Rafael

AU - Henning, Thomas

AU - Jordán, Andrés

AU - Stoeva, Denitza

AU - Jones, Matías I.

AU - Acuña-Aguirre, Lorena

AU - Stefanov, Stefan

AU - Tala Pinto, M.

AU - Hobson, Melissa J.

AU - Espinoza, Nestor

AU - Rojas, Felipe I.

AU - Schlecker, Martin

AU - Bozhilov, Vladimir

AU - Guillot, Tristan

AU - Triaud, Amaury H. M. J.

AU - Lissauer, Jack J.

AU - Korth, Judith

AU - Parviainen, Hannu

AU - Kreidberg, Laura

AU - Bendjoya, Philippe

AU - Suarez, Olga

AU - Ziegler, Carl

AU - Rowden, Pamela

AU - Rudat, Alexander

AU - Kostov, Veselin

AU - Winn, Joshua N.

AU - Jenkins, Jon M.

AU - Collins, Karen A.

AU - Watkins, Cristilyn N.

AU - Radford, Don J.

AU - Stockdale, Chris

AU - Gan, Tianjun

N1 - Based on observations collected at the European Organization for Astronomical Research in the Southern Hemisphere under MPG programmes 0102.A-9006, 0103.A-9008, 0104.A-9007

PY - 2026/3/2

Y1 - 2026/3/2

N2 - TOI-1232 is a G dwarf star with a mass of 1.06−0.06+0.07M⊙ , a radius of 1.07 ± 0.05 R⊙, and a slightly higher metallicity than solar of Fe/H = 0.18 ± 0.05. The star hosts a transiting warm Jovian-mass planet, TOI-1232 b, with an orbital period of Pb = 14.256−0.001+0.001 days, identified with data from multiple sectors of the TESS space telescope. The TESS light curve of TOI-1232 is complex, as it is contaminated by a background eclipsing binary with a period of 1.37 days. TOI-1232 b was firmly confirmed by ground-based transit follow-up campaigns from the Las Cumbres, Hazelwood, Brierfield, and ASTEP observatories. Additionally, the TESS transits of TOI-1232 b exhibit strong transit-timing variations (TTVs) with a superperiod of 235.5 ± 0.7 days and a semiamplitude of 27 minutes. Radial velocity (RV) follow-up with the FEROS spectrograph confirms the planetary nature of the transiting candidate, while a self-consistent N-body analysis of RVs and TTVs pinpoints the presence of a second outer Saturn-mass companion, TOI-1232 c with a period of Pc = 30.356−0.012+0.010 days. The TOI-1232 warm-giant system is particularly important due to the evidence of two massive planets that reside near the 2:1 commensurability but are not locked in a mean-motion resonance. Thanks to TESS, we have revealed a handful of these rare systems. Hence, TOI-1232 is an important addition to understanding the formation and dynamical evolution of such compact, massive, warm giant planets.

AB - TOI-1232 is a G dwarf star with a mass of 1.06−0.06+0.07M⊙ , a radius of 1.07 ± 0.05 R⊙, and a slightly higher metallicity than solar of Fe/H = 0.18 ± 0.05. The star hosts a transiting warm Jovian-mass planet, TOI-1232 b, with an orbital period of Pb = 14.256−0.001+0.001 days, identified with data from multiple sectors of the TESS space telescope. The TESS light curve of TOI-1232 is complex, as it is contaminated by a background eclipsing binary with a period of 1.37 days. TOI-1232 b was firmly confirmed by ground-based transit follow-up campaigns from the Las Cumbres, Hazelwood, Brierfield, and ASTEP observatories. Additionally, the TESS transits of TOI-1232 b exhibit strong transit-timing variations (TTVs) with a superperiod of 235.5 ± 0.7 days and a semiamplitude of 27 minutes. Radial velocity (RV) follow-up with the FEROS spectrograph confirms the planetary nature of the transiting candidate, while a self-consistent N-body analysis of RVs and TTVs pinpoints the presence of a second outer Saturn-mass companion, TOI-1232 c with a period of Pc = 30.356−0.012+0.010 days. The TOI-1232 warm-giant system is particularly important due to the evidence of two massive planets that reside near the 2:1 commensurability but are not locked in a mean-motion resonance. Thanks to TESS, we have revealed a handful of these rare systems. Hence, TOI-1232 is an important addition to understanding the formation and dynamical evolution of such compact, massive, warm giant planets.

KW - Transit timing variation method

KW - Radial velocity

KW - Transit photometry

KW - Exoplanet dynamics

U2 - 10.3847/1538-3881/ae2312

DO - 10.3847/1538-3881/ae2312

M3 - Article

SN - 0004-6256

VL - 171

JO - The Astronomical Journal

JF - The Astronomical Journal

IS - 3

M1 - 173

ER -

A Warm Massive Pair of Planets around TOI-1232 Revealed with Transit-timing Variations and Doppler Spectroscopy

Abstract

Bibliographical note

Keywords

Access to Document

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Projects

Temperate planets from Chile & Antarctica

An upgrade to the mount of the ASTEP telescope

H2020_ERC_BEBOP

Red-Enhanced Cameras to Seek Rocky Planets Transiting Ultra-Cool Dwarfs

Cite this