J/AJ/168/294ivo://CDS.VizieR/J/AJ/168/294doi:10.26093/cds/vizier/be-58-96CDSMasuda K.Libby-Roberts J.E.Livingston J.H.Stevenson K.B.Gao P.,Vissapragada S.Fu G.Han TeGreklek-McKeon M.Mahadevan S.Agol E.,Bello-Arufe A.Berta-Thompson Z.Canas C.I.Chachan Y.Hebb L.Hu R.,Kawashima Y.Knutson H.A.Morley C.V.Murray C.A.Ohno K.,Tokadjian A.Zhang XiWelbanks L.Nixon M.C.Freedman R.Narita N.,Fukui A.de Leon J.P.Mori M.Palle E.Murgas F.Parviainen H.,Esparza-Borges E.Jontof-Hutter D.Collins K.A.Benni P.Barkaoui K.,Pozuelos F.J.Gillon M.Jehin E.Benkhaldoun Z.Hawley S.Lin A.S.J.,Stefansson G.Bieryla A.Yilmaz M.Senavci H.V.Girardin E.,Marino G.Wang G.2026-07-02T11:45:11Z2025-09-18T12:55:27ZCDS support team

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

cds-question@unistra.frexoplanetsinfrared-photometryvisible-astronomyKepler-51 is a <=1Gyr old Sun-like star hosting three transiting planets with radii ~6-9R_{Earth}_ and orbital periods ~45-130days. Transit timing variations (TTVs) measured with past Kepler and Hubble Space Telescope (HST) observations have been successfully modeled by considering gravitational interactions between the three transiting planets, yielding low masses and low mean densities (<=0.1g/cm^3^) for all three planets. However, the transit time of the outermost transiting planet Kepler-51d recently measured by the James Webb Space Telescope 10yr after the Kepler observations is significantly discrepant from the prediction made by the three-planet TTV model, which we confirmed with ground-based and follow-up HST observations. We show that the departure from the three-planet model is explained by including a fourth outer planet, Kepler-51e, in the TTV model. A wide range of masses (<=M_Jup_) and orbital periods (<=10yr) are possible for Kepler-51e. Nevertheless, all the coplanar solutions found from our brute-force search imply masses <=10M_{Earth}_ for the inner transiting planets. Thus, their densities remain low, though with larger uncertainties than previously estimated. Unlike other possible solutions, the one in which Kepler-51e is around the 2:1 mean motion resonance with Kepler-51d implies low orbital eccentricities (<=0.05) and comparable masses (~5M_{Earth}_) for all four planets, as is seen in other compact multiplanet systems. This work demonstrates the importance of long-term follow-up of TTV systems for probing longer-period planets in a system.2024AJ....168..294Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/168/294CatalogResearchIsServedByTAP VizieR generic servicerelated-toI/357 : Gaia DR3 Part 3. Non-single stars (Gaia Collaboration, 2022)VII/233 : 2MASS All-Sky Extended Src Cat. (XSC) (IPAC/UMass, 2003-2006)J/A+A/546/A14 : Limb-darkening for CoRoT, Kepler, Spitzer (Claret+, 2012)J/ApJS/204/24 : Kepler planetary candidates. III. (Batalha+, 2013)J/MNRAS/436/1883 : Properties of KOI host stars (Walkowicz+, 2013)J/ApJ/790/146 : Planets in Kepler's multi-transiting systems (Fabrycky+, 2014)J/ApJ/787/80 : 139 Kepler planets transit time variations (Hadden+, 2014)J/ApJS/211/24 : Rotation periods of Kepler MS stars (McQuillan+, 2014)J/ApJS/225/9 : Kepler TTVs. IX. The full long-cadence dataset (Holczer+, 2016)J/AJ/154/5 : Transit timing variations of 145 Kepler planets (Hadden+, 2017)J/AJ/154/107 : California-Kepler Survey (CKS). I. 1305 stars (Petigura+, 2017)J/ApJS/237/38 : Extended abundance analysis of KOIs (Brewer+, 2018)J/AJ/155/48 : California-Kepler Survey (CKS).V. Masses & radii (Weiss+, 2018)J/AJ/157/43 : WASP-161b, WASP-163b and WASP-170b (Barkaoui+, 2019)J/AJ/157/52 : Radial velocity obs. in super-Earth systems (Bryan+, 2019)J/AJ/158/133 : Transit timing and light curves for K2-146 (Hamann+, 2019)J/AJ/159/57 : HST spec. LCs of Kepler 51b & 51d (Libby-Roberts+, 2020)J/MNRAS/505/1293 : Duration measurements analysis KOIs planets (Shahaf+, 2021)J/AJ/163/179 : The California-Kepler Survey. X. (Petigura+, 2022)J/AJ/165/33 : HIRES TOI-1136s planets & planet b RVs (Dai+, 2023)J/AJ/165/48 : Transit times for Kepler-289 b, c and d (Greklek-McKeon+, 2023)J/AJ/168/93 : Phot. follow-up of TOI-2015 & discov. of TOI-2015b (Jones+, 2024)http://archive.stsci.edu/ : Mikulski Archive for Space Telescopeshttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/168/294https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/168/294http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/168/294https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/168/294https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/168/294http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/168/294GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/AJ/168/294/table7Future predicted transit times of Kepler-51b, c, and d based on the 2:1 solutions and all solutions from the brute-force searchrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDPlanet identifiermeta.id;meta.maincharBJD-outMean Barycentric Julian Date of transit time for outside 2:1 solutiondtime.epochdoublee_BJD-outStandard deviation in BJD-outdstat.error;time.epochdoubleBJD-inMean Barycentric Julian Date of transit time for inside 2:1 solutiondtime.epochdoublee_BJD-inStandard deviation in BJD-indstat.error;time.epochdoubleBJD-allMean Barycentric Julian Date of transit time for all solutions from the brute-force searchdtime.epochdoublee_BJD-allStandard deviation in BJD-alldstat.error;time.epochdouble