2026-07-27T02:06:19Zivo://CDS.VizieR/J/A+A/709/A2652026-05-25T00:52:01ZJ.A_AIVOARVs and photometry light curves of TOI-5624Following 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 P_b_~3.4, P_c_~7.9, P_d_~13.7, and P_e_~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 R_b_=2.314+/-0.035R_{Earth}_, R_c_=2.474+/-0.042R_{Earth}_, R_d_=3.584_-0.050_^+0.051^ R_{Earth}_, and R_e_=3.247_-0.043_^+0.042^ R_{Earth}_ and masses of M_b_=9.4+/-1.4M_{Earth}_, M_c_=4.8+/-1.9M_{Earth}, M_d_=4.9+/-2.2M_{Earth}_, and M_e_=8.9_-3.0_^+2.9^M_{Earth}_. 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 M_f_*sini_f_=13.0+/-3.7M_{Earth}_. 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 (>3{sigma}) 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.multiple-starsexoplanetsphotometryradial-velocityspectroscopyvisible-astronomyinfrared-astronomyline-intensitiesexoplanet-astronomystellar-astronomyobservational-astronomyinterdisciplinary-astronomyhttps://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/A+A/709/A265https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/709/A2652026A&A...709A.265Bhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/709/A265Bonfanti 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.CDS2026https://cds.unistra.fr/vizier-org/licences_vizier.htmlCDS support team <cds-question@unistra.fr>DatasetAstroObjectsastronomy