Hidden Gems in TESS: SHERLOCK finds two new rocky planets around nearby M dwarfs

M. Timmermans; M. Dévora-Pajares; F. J. Pozuelos; K. Barkaoui; B. Rojas-Ayala; J. M. Almenara; S. B. Howell; A. H. M. J. Triaud; M. Gillon; M. G. Scott; Y. T. Davis; B. V. Rackham; A. J. Burgasser; X. Bonfils; K. A. Collins; B. -O. Demory; G. Dransfield; E. Ducrot; A. Fukui; M. Ghachoui; Y. Gómez Maqueo Chew; E. Jehin; N. Narita; P. P. Pedersen; R. P. Schwarz; G. Srdoc; S. Yalcinkaya; Z. Way

doi:10.1093/mnras/stag710

Hidden Gems in TESS: SHERLOCK finds two new rocky planets around nearby M dwarfs

M. Timmermans^*
, M. Dévora-Pajares
, F. J. Pozuelos
, K. Barkaoui
, B. Rojas-Ayala
, J. M. Almenara
, S. B. Howell
, A. H. M. J. Triaud
, M. Gillon
, M. G. Scott
, Y. T. Davis
, B. V. Rackham
, A. J. Burgasser
, X. Bonfils
, K. A. Collins
, B. -O. Demory
, G. Dransfield
, E. Ducrot
, A. Fukui
, M. Ghachoui

Y. Gómez Maqueo Chew, E. Jehin, N. Narita, P. P. Pedersen, R. P. Schwarz, G. Srdoc, S. Yalcinkaya, Z. Way

^*Corresponding author for this work

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

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Abstract

The Hidden Gems project searches the TESS data for additional planets transiting low-mass stars in confirmed systems. Our goal is to identify planet candidates that are below the detection threshold set by the SPOC and QLP pipelines using sherlock, a specialized pipeline for robust detection and vetting of transit signals in TESS data. We present the discovery of two inner rocky planets in the TOI-237 and TOI-4336 A systems, validated with ground-based photometry from the TRAPPIST, SPECULOOS, ExTrA, and LCO facilities. TOI-237 c has a radius of 1.21 ± 0.04R_⊕⁠, orbits its mid-M host star every 1.74 d, and is close to a 3:1 mean-motion resonance with TOI-237 b. TOI-4336 A c has a radius of 1.17 ± 0.06 R_⊕⁠, and orbits with a period of 7.58 d an M3.5 host star which is part of a hierarchical triple system. We performed model comparison to search for non-zero eccentricities, and found that the circular transit models are statistically favoured. Dynamical simulations show that both systems are in stable configurations, and the transit timing variations expected for the TOI-237 system are of the order of seconds. TOI-237 c and TOI-4336 A c join the high-interest population of warm likely super-Earths below the so-called radius valley. In particular, TOI-237 c is a good candidate for phase curve observations with JWST/MIRI thanks to the small radius of the host star and its short period.

Original language	English
Article number	stag710
Number of pages	20
Journal	Monthly Notices of the Royal Astronomical Society
Early online date	15 Apr 2026
DOIs	https://doi.org/10.1093/mnras/stag710
Publication status	Published - Jun 2026

Bibliographical note

This is a coordinated pre-print submission with Parc et al. 2026

Keywords

astro-ph.EP

Access to Document

10.1093/mnras/stag710Licence: Creative Commons: Attribution (CC BY)

TimmermansM2026HiddenFinal published version, 4.1 MBLicence: Creative Commons: Attribution (CC BY)

1 Active
2 Finished

Temperate planets from Chile & Antarctica
Triaud, A. (Principal Investigator)
SCIENCE & TECHNOLOGY FACILITIES COUNCIL
1/04/24 → 31/03/27
Project: Research
Running Costs of the Ganymede Telescope
Triaud, A. (Principal Investigator)
SCIENCE & TECHNOLOGY FACILITIES COUNCIL
1/04/21 → 31/03/24
Project: Research Councils
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

Timmermans, M., Dévora-Pajares, M., Pozuelos, F. J., Barkaoui, K., Rojas-Ayala, B., Almenara, J. M., Howell, S. B., Triaud, A. H. M. J., Gillon, M., Scott, M. G., Davis, Y. T., Rackham, B. V., Burgasser, A. J., Bonfils, X., Collins, K. A., Demory, B. .-O., Dransfield, G., Ducrot, E., Fukui, A., ... Way, Z. (2026). Hidden Gems in TESS: SHERLOCK finds two new rocky planets around nearby M dwarfs. Monthly Notices of the Royal Astronomical Society, Article stag710. https://doi.org/10.1093/mnras/stag710

@article{1fd4a1671a264bc284b6a655bcdb8b72,

title = "Hidden Gems in TESS: SHERLOCK finds two new rocky planets around nearby M dwarfs",

abstract = "The Hidden Gems project searches the TESS data for additional planets transiting low-mass stars in confirmed systems. Our goal is to identify planet candidates that are below the detection threshold set by the SPOC and QLP pipelines using sherlock, a specialized pipeline for robust detection and vetting of transit signals in TESS data. We present the discovery of two inner rocky planets in the TOI-237 and TOI-4336 A systems, validated with ground-based photometry from the TRAPPIST, SPECULOOS, ExTrA, and LCO facilities. TOI-237 c has a radius of 1.21 ± 0.04R⊕⁠, orbits its mid-M host star every 1.74 d, and is close to a 3:1 mean-motion resonance with TOI-237 b. TOI-4336 A c has a radius of 1.17 ± 0.06 R⊕⁠, and orbits with a period of 7.58 d an M3.5 host star which is part of a hierarchical triple system. We performed model comparison to search for non-zero eccentricities, and found that the circular transit models are statistically favoured. Dynamical simulations show that both systems are in stable configurations, and the transit timing variations expected for the TOI-237 system are of the order of seconds. TOI-237 c and TOI-4336 A c join the high-interest population of warm likely super-Earths below the so-called radius valley. In particular, TOI-237 c is a good candidate for phase curve observations with JWST/MIRI thanks to the small radius of the host star and its short period.",

keywords = "astro-ph.EP",

author = "M. Timmermans and M. D{\'e}vora-Pajares and Pozuelos, \{F. J.\} and K. Barkaoui and B. Rojas-Ayala and Almenara, \{J. M.\} and Howell, \{S. B.\} and Triaud, \{A. H. M. J.\} and M. Gillon and Scott, \{M. G.\} and Davis, \{Y. T.\} and Rackham, \{B. V.\} and Burgasser, \{A. J.\} and X. Bonfils and Collins, \{K. A.\} and Demory, \{B. -O.\} and G. Dransfield and E. Ducrot and A. Fukui and M. Ghachoui and Chew, \{Y. G{\'o}mez Maqueo\} and E. Jehin and N. Narita and Pedersen, \{P. P.\} and Schwarz, \{R. P.\} and G. Srdoc and S. Yalcinkaya and Z. Way",

note = "This is a coordinated pre-print submission with Parc et al. 2026",

year = "2026",

month = jun,

doi = "10.1093/mnras/stag710",

language = "English",

journal = "Monthly Notices of the Royal Astronomical Society",

issn = "0035-8711",

publisher = "SIPRI/Oxford University Press",

}

Timmermans, M, Dévora-Pajares, M, Pozuelos, FJ, Barkaoui, K, Rojas-Ayala, B, Almenara, JM, Howell, SB, Triaud, AHMJ, Gillon, M, Scott, MG, Davis, YT, Rackham, BV, Burgasser, AJ, Bonfils, X, Collins, KA, Demory, B-O, Dransfield, G, Ducrot, E, Fukui, A, Ghachoui, M, Chew, YGM, Jehin, E, Narita, N, Pedersen, PP, Schwarz, RP, Srdoc, G, Yalcinkaya, S & Way, Z 2026, 'Hidden Gems in TESS: SHERLOCK finds two new rocky planets around nearby M dwarfs', Monthly Notices of the Royal Astronomical Society. https://doi.org/10.1093/mnras/stag710

TY - JOUR

T1 - Hidden Gems in TESS

T2 - SHERLOCK finds two new rocky planets around nearby M dwarfs

AU - Timmermans, M.

AU - Dévora-Pajares, M.

AU - Pozuelos, F. J.

AU - Barkaoui, K.

AU - Rojas-Ayala, B.

AU - Almenara, J. M.

AU - Howell, S. B.

AU - Triaud, A. H. M. J.

AU - Gillon, M.

AU - Scott, M. G.

AU - Davis, Y. T.

AU - Rackham, B. V.

AU - Burgasser, A. J.

AU - Bonfils, X.

AU - Collins, K. A.

AU - Demory, B. -O.

AU - Dransfield, G.

AU - Ducrot, E.

AU - Fukui, A.

AU - Ghachoui, M.

AU - Chew, Y. Gómez Maqueo

AU - Jehin, E.

AU - Narita, N.

AU - Pedersen, P. P.

AU - Schwarz, R. P.

AU - Srdoc, G.

AU - Yalcinkaya, S.

AU - Way, Z.

N1 - This is a coordinated pre-print submission with Parc et al. 2026

PY - 2026/6

Y1 - 2026/6

N2 - The Hidden Gems project searches the TESS data for additional planets transiting low-mass stars in confirmed systems. Our goal is to identify planet candidates that are below the detection threshold set by the SPOC and QLP pipelines using sherlock, a specialized pipeline for robust detection and vetting of transit signals in TESS data. We present the discovery of two inner rocky planets in the TOI-237 and TOI-4336 A systems, validated with ground-based photometry from the TRAPPIST, SPECULOOS, ExTrA, and LCO facilities. TOI-237 c has a radius of 1.21 ± 0.04R⊕⁠, orbits its mid-M host star every 1.74 d, and is close to a 3:1 mean-motion resonance with TOI-237 b. TOI-4336 A c has a radius of 1.17 ± 0.06 R⊕⁠, and orbits with a period of 7.58 d an M3.5 host star which is part of a hierarchical triple system. We performed model comparison to search for non-zero eccentricities, and found that the circular transit models are statistically favoured. Dynamical simulations show that both systems are in stable configurations, and the transit timing variations expected for the TOI-237 system are of the order of seconds. TOI-237 c and TOI-4336 A c join the high-interest population of warm likely super-Earths below the so-called radius valley. In particular, TOI-237 c is a good candidate for phase curve observations with JWST/MIRI thanks to the small radius of the host star and its short period.

AB - The Hidden Gems project searches the TESS data for additional planets transiting low-mass stars in confirmed systems. Our goal is to identify planet candidates that are below the detection threshold set by the SPOC and QLP pipelines using sherlock, a specialized pipeline for robust detection and vetting of transit signals in TESS data. We present the discovery of two inner rocky planets in the TOI-237 and TOI-4336 A systems, validated with ground-based photometry from the TRAPPIST, SPECULOOS, ExTrA, and LCO facilities. TOI-237 c has a radius of 1.21 ± 0.04R⊕⁠, orbits its mid-M host star every 1.74 d, and is close to a 3:1 mean-motion resonance with TOI-237 b. TOI-4336 A c has a radius of 1.17 ± 0.06 R⊕⁠, and orbits with a period of 7.58 d an M3.5 host star which is part of a hierarchical triple system. We performed model comparison to search for non-zero eccentricities, and found that the circular transit models are statistically favoured. Dynamical simulations show that both systems are in stable configurations, and the transit timing variations expected for the TOI-237 system are of the order of seconds. TOI-237 c and TOI-4336 A c join the high-interest population of warm likely super-Earths below the so-called radius valley. In particular, TOI-237 c is a good candidate for phase curve observations with JWST/MIRI thanks to the small radius of the host star and its short period.

KW - astro-ph.EP

U2 - 10.1093/mnras/stag710

DO - 10.1093/mnras/stag710

M3 - Article

SN - 0035-8711

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

M1 - stag710

ER -

Hidden Gems in TESS: SHERLOCK finds two new rocky planets around nearby M dwarfs

Abstract

Bibliographical note

Keywords

Access to Document

Fingerprint

Projects

Temperate planets from Chile & Antarctica

Running Costs of the Ganymede Telescope

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

Cite this