J/A+A/709/A265 RVs and photometry light curves of TOI-5624 (Bonfanti+, 2026)
The multi-planet system TOI-5624: four transiting sub-Neptunes with an outer
companion revealed by transit-timing variations.
Bonfanti A., Gandolfi D., Leonardi P., Osborn H.P., Serrano L.M.,
Hebrard G., Billot N., Bekkelien A., Olofsson G., Broeg C., Nardiello D.,
Sousa S.G., Wilson T.G., Correia A.C.M., Pezzotti C., Brandeker A.,
Fossati L., Gillon M., Stalport M., Akinsanmi B., Alibert Y., Alonso R.,
Asquier J., Barczy T., Barrado D., Barros S.C.C., Baumjohann W., Benz W.,
Borsato L., Castro-Gonzalez A., Collier Cameron A., Csizmadia Sz.,
Cubillos P.E., Davies M.B., Deleuil M., Delfosse X., Deline A.,
Demangeon O.D.S., Demory B.-O., Derekas A., Destriez F., Edwards B.,
Ehrenreich D., Erikson A., Fortier A., Fridlund M., Gazeas K., Gudel M.,
Gunther M.N., Hara N., Heidari N., Heitzmann A., Helling C., Isaak K.G.,
Keller T., Kiss L.L., Kitzmann D., Korth J., Lacedelli G., Lam K.W.F.,
Laskar J., Lecavelier des Etangs A., Leleu A., Lendl M., Magrin D.,
Maxted P.F.L., Mecina M., Merin B., Mordasini C., Nascimbeni V.,
Ottensamer R., Pagano I., Palle E., Peter G., Piazza D., Piotto G.,
Pollacco D., Queloz D., Ragazzoni R., Rando N., Rauer H., Ribas I.,
Santos N.C., Scandariato G., Segransan D., Simon A.E., Smith A.M.S.,
Sulis S., Szabo Gy.M., Udry S., Ulmer-Moll S., Van Grootel V.,
Venturini J., Verrecchia F., Villaver E., Walton N.A., Wolf S.,
Wolter D., Zingales T.
<Astron. Astrophys. 709, A265 (2026)>
=2026A&A...709A.265B 2026A&A...709A.265B (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Photometry ;
Radial velocities ; Spectroscopy ; Optical ; Infrared ;
Equivalent widths
Keywords: techniques: photometric - techniques: radial velocities -
planets and satellites: fundamental parameters -
stars: fundamental parameters
Abstract:
Following the 2022 alert of a TESS object of interest transiting
TOI-5624 (a G7, Vstar ∼100pc away), a CHEOPS campaign in 2023
detected four planetary signals at Pb∼3.4, Pc∼7.9,
Pd∼13.7, and Pe∼21.5 days, later confirmed by additional TESS
and CHEOPS photometry in 2024-2025. By using TESS and CHEOPS
photometry along with HARPS-N and SOPHIE high-resolution spectra, we
determined the planet properties and performed a dynamical analysis of
the system. After analysing the photometric data, we extracted and
modelled the radial velocity (RV) time series using two independent
methodologies both within a Markov chain Monte Carlo framework. We
further integrated the N-body equations of motion, while
simultaneously fitting the transit times and the detrended RVs, to
dynamically characterise the system. We present the discovery of four
transiting sub-Neptunes with radii of
Rb=2.314±0.035R⊕, Rc=2.474±0.042R⊕,
Rd=3.584-0.050+0.051 R⊕, and
Re=3.247-0.043+0.042 R⊕ and masses of
Mb=9.4±1.4M⊕, Mc=4.8±1.9M_⊕,
Md=4.9±2.2M⊕, and Me=8.9-3.0+2.9M⊕.
Our photometric analysis reveals that the outermost transiting planet
TOI-5624e shows significant transit time variations (TTVs). Indeed, we
find a robust Keplerian signal in the RV time series close to the 2:1
period commensurability with TOI-5624e, which explains the TTV pattern
exhibited by TOI-5624e according to our dynamical analysis. We label
this non-transiting planet as TOI-5624f and find its minimum mass to
be Mf*sinif=13.0±3.7M⊕. Among the known systems
hosting more than four planets, the remarkable precision with which
the radii have been measured (<1.7%) and the firm assessment
(>3σ) of the mass for at least three planets has been previously
reached only for TRAPPIST-1. Additional photometric observations will
enable a better sample of the TTV modulation and a more robust
dynamical determination of the masses.
Description:
Appendix of the paper reporting, tablea1.dat the RV time
series as extracted from the HARPS-N spectra, tablea2.dat the RV time
series as extracted from the SOPHIE spectra, ch1-36.dat the detrended
CHEOPS LCs.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tablea1.dat 69 96 RV time series extracted from HARPS-N
tablea2.dat 69 26 RV time series extracted from SOPHIE
lc/* * 36 CHEOPS detrended LCs 1 to 36
list.dat 38 36 CHEOPS detrended LCs file list
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 F13.6 d BJD Observation time as BJD TDB (BJD-2450000)
15- 21 F7.3 m/s RV RVs extracted from HARPS-N CCFs as SN fit
23- 27 F5.3 m/s e_RV Errors on the RVs
29- 33 F5.3 km/s FWHM-SN FWHM of the fitted skew-Normal function
35- 40 F6.3 0.1nm Ha H-alpha inferred from spectra
42- 48 F7.4 --- gamma Skewness of the fitted skew-Normal function
50- 55 F6.3 0.1nm NaD2 NaD2 inferred from spectra
57- 63 F7.3 m/s RVd Detrended normalized RVs
65- 69 F5.3 m/s e_RVd Errors on the detrended RVs with jitter effect
included
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Byte-by-byte Description of file: tablea2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 F13.6 d BJD Observation time as BJD TDB (BJD-2450000)
15- 21 F7.3 m/s RV RVs extracted from SOPHIE CCFs as Gaussian fit
23- 27 F5.3 m/s e_RV Error on the RV
29- 33 F5.3 km/s FWHM FWHM of the fitted Gaussian
35- 40 F6.3 % A Contrast of the fitted Gaussian
42- 48 F7.4 --- Bis Bisector inferred from the fitted Gaussian
50- 55 F6.3 [-] logRHK logRHK inferred from spectra
57- 63 F7.3 m/s RVd Detrended normalized RV
65- 69 F5.3 m/s e_RVd Error on the detrended RV jitter included
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Byte-by-byte Description of file: lc/*
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 14 F14.6 d BJD Observation time as BJD TDB (BJD-2450000)
16- 23 F8.6 --- Flux Detrended normalized flux
25- 32 F8.6 --- e_Flux Flux error
34- 42 F9.6 --- Res Residuals wrt transit model
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Byte-by-byte Description of file: list.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- FileName LC file name in lc directory
10- 23 F14.6 d BJDmin Minimum observation time as BJD TDB
(JD-2450000)
25- 38 F14.6 d BJDmax Maximum observation time as BJD TDB
(JD-2450000)
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Acknowledgements:
Andrea Bonfanti, Andrea.Bonfanti(at)oeaw.ac.at
License: CC-BY-4.0 [see https://spdx.org/licenses/]
(End) Andrea Bonfanti [OeAW, Austria], Luc Trabelsi [CDS] 14-Apr-2026