J/AJ/169/246ivo://CDS.VizieR/J/AJ/169/246CDSLarsen A.Swaby T.N.Kobulnicky H.A.Canas C.I.Kanodia S.,Libby-Roberts J.Monson A.Gupta A.F.Cochran W.Mahadevan S.,Bender C.Diddams S.A.Halverson S.Lin A.S.J.Moe M.Ninan J.,Robertson P.Roy A.Schwab C.Stefansson G.2026-03-02T06:25:50Z2026-01-23T16:47:46ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frbrown-dwarfsradial-velocityphotometryvisible-astronomyinfrared-astronomyspectroscopydwarf-starsm-starsBrown dwarfs bridge the gap between stars and planets, providing valuable insight into both planetary and stellar-formation mechanisms. Yet the census of transiting brown-dwarf companions, in particular around M-dwarf stars, remains incomplete. We report the discovery of two transiting brown dwarfs around low-mass hosts using a combination of space- and ground-based photometry along with near-infrared radial velocities. We characterize TOI-5389Ab (68.0_-2.2_^+2.2^M_J_) and TOI-5610b (40.4_-1.0_^+1.0^M_J_), two moderately massive brown dwarfs orbiting early M-dwarf hosts (Teff=3569+/-59K and 3618+/-59K, respectively). For TOI-5389Ab, the best fitting parameters are period P=10.40046+/-0.00002d, radius R_BD_=0.824_-0.031_^+0.033^R_J_, and low eccentricity e=0.0962_-0.0046_^+0.0027^. In particular, this constitutes one of the most extreme substellar-stellar companion-to-host mass ratios of q=0.150. For TOI-5610b, the best-fitting parameters are period P=7.95346+/-0.00002d, radius R_BD_=0.887_-0.031_^+0.031^R_J_, and moderate eccentricity e=0.354_-0.012_^+0.011^. Both targets are expected to have shallow, but potentially observable, occultations: <=500ppm in the Johnson K band. A statistical analysis of M-dwarf/BD systems reveals for the first time that those at short orbital periods (P<13d) exhibit a dearth of 13M_J_<M_BD_<40M_J_ companions (q<0.1) compared to those at slightly wider separations.2025AJ....169..246Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/169/246CatalogResearchIsServedByTAP VizieR generic servicerelated-toI/357 : Gaia DR3 Part 3. Non-single stars (Gaia Collaboration, 2022)VII/233 : 2MASS All-Sky Extended Source Catalog (XSC) (IPAC/UMass, 2003-2006)V/130 : Geneva-Copenhagen Surv. of Solar neighbourhood III (Holmberg+, 2009)J/ApJ/640/1051 : 25pc sample of Sun-like stars (Grether+, 2006)J/AJ/132/1221 : VJHK and SDSS photometry of DA white dwarfs (Holberg+, 2006)J/AJ/142/19 : Speckle observations of KOI (Howell+, 2011)J/A+A/525/A95 : Search for brown-dwarf companions of stars (Sahlmann+, 2011)J/ApJ/730/128 : Spectroscopy of DA WD from the SDSS-DR4 (Tremblay+, 2011)J/ApJ/757/112 : Stellar diameters. II. K and M-stars (Boyajian+, 2012)J/ApJ/771/129 : Submillimetric Class II sources of Taurus (Andrews+, 2013)J/A+A/549/A109 : HARPS XXXI. The M-dwarf sample (Bonfils+, 2013)J/ApJ/788/48 : X-ray through NIR photometry of NGC 2617 (Shappee+, 2014)J/ApJ/807/45 : Potentially habitable planets orbit. M dwarfs (Dressing+, 2015)J/ApJ/814/130 : Planet occurrence rates calculated for KOIs (Mulders+, 2015)J/ApJ/831/125 : ALMA 887um obs. of ChaI star-forming region (Pascucci+, 2016)J/A+A/587/A64 : Physical properties of giant exoplanets (Santerne+, 2016)J/A+A/603/A30 : Evidence for 2 distinct giant planet population (Santos+, 2017)J/MNRAS/475/1960 : ESPaDOnS spectropolarimeter obs. of M dwarfs (Fouque+, 2018)J/MNRAS/474/4322 : Orbital parameters of 341 new binaries (Murphy+, 2018)J/AJ/158/75 : Mid-type M dwarfs planet occurr. rates (Hardegree-Ullman+, 2019)J/AJ/158/13 : The first 300 stars observed by the GPIES (Nielsen+, 2019)J/ApJ/901/93 : Model atmos. analysis of hot WDs from SDSS DR12 (Bedard+, 2020)J/MNRAS/491/5216 : Rot. periods for 107 M dwarfs from APACHE (Giacobbe+, 2020)J/AJ/159/100 : Flux & RVs of the dwarf G9-40 with K2 & HPF (Stefansson+, 2020)J/A+A/652/A127 : 13-150MJ eclipsing binaries transiting comp. (Grieves+, 2021)J/A+A/645/A7 : Determining true mass of RV exoplanets with Gaia (Kiefer+, 2021)J/A+A/650/A201 : 10 parsec sample in the Gaia era first update (Reyle+, 2021)J/ApJS/259/33 : Faint-star TOIs from the TESS Primary Mission (Kunimoto+, 2022)J/A+A/658/A194 : Stellar parameters of 18 M dwarfs (Passegger+, 2022)J/AJ/167/109 : TOI-1994 radial velocities with MINERVA & CHIRON (Page+, 2024)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/169/246https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/169/246http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/169/246https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/169/246https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/169/246http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/169/246GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/AJ/169/246/table1TOI-5389Ab RBO photometric datarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBJD[2460004/2460348] Barycentric Julian Date at TDBdtime.epochdoubleFlux[0.9/1.1] Normalized flux (Bessell I)phot.flux;arith.ratio;em.opt.Idoublee_Flux[0.008/0.042] Uncertainty in Fluxstat.error;phot.flux;arith.ratiodoubleJ/AJ/169/246/table2TOI-5610b RBO photometric datarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBJD[2460312/2460353] Barycentric Julian Date at TDBdtime.epochdoubleFlux[0.93/1.08] Normalized flux (Bessell I)phot.flux;arith.ratio;em.opt.Idoublee_Flux[0.008/0.058] Uncertainty in Fluxstat.error;phot.flux;arith.ratiodoubleJ/AJ/169/246/table3Barycentric HPF radial velocity measurements for TOI-5389AbrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBJD[2459921/2460307] Barycentric Julian Date at TDBdtime.epochdoubleRVel[2424/22399] Barycentric-corrected radial velocitym/sspect.dopplerVelocinte_RVel[15/81] Uncertainty in RVelm/sstat.error;spect.dopplerVelocintJ/AJ/169/246/table4Barycentric HPF radial velocity measurements for TOI-5610brecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBJD[2459897/2460305] Barycentric Julian Date at TDBdtime.epochdoubleRVel[37125/49730] Barycentric-corrected radial velocitym/sspect.dopplerVelocinte_RVel[5/23] Uncertainty in RVelm/sstat.error;spect.dopplerVelocint