J/MNRAS/541/714ivo://CDS.VizieR/J/MNRAS/541/714doi:10.26093/cds/vizier/bg-gx-paCDSBasturk O.Kutluay A.C.Barker A.Yalcinkaya S.Southworth J.,Barkaoui K.Wunsche A.Burgdorf M.J.Timmermans M.Jehin E.,Tregloan-Reed J.Jaimes R.F.Hinse T.C.Duru B.Hitchcock J.,Longa-Pena P.Rahvar S.Sajadian S.Bretton M.Selam S.O.Gillon M.,Bonavita M.D'Ago G.Dominik M.Jorgensen U.G.Snodgrass C.,Spyratos P.Mancini L.2026-08-03T07:33:29Z2025-10-21T11:46:43ZCDS support team

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

cds-question@unistra.frmultiple-starsexoplanetsphotometryvisible-astronomyWASP-4 b is a hot Jupiter exhibiting a decreasing orbital period, prompting investigations into potential mechanisms driving its evolution. We analysed 173 transit light curves, including 37 new observations, and derived mid-transit timings with exofast, forming the most extensive transit timing variation (TTV) data set for this system. Adding 58 literature timings and removing unreliable data, we constructed a TTV diagram with 216 points. Our analysis considered linear, quadratic, and apsidal motion models, with the quadratic model proving to be significantly superior in all model comparison statistics. We found no significant periodic signals in the data. The quadratic model allows us to infer a tidal quality factor of Q'_*r_~80000 from the orbital decay rate if this is due to stellar tides. Theoretical considerations indicate that such efficient dissipation is possible due to internal gravity waves in the radiative core of WASP-4, but only in our models with a more evolved host star, possibly near the end of its main-sequence lifetime, and with a larger radius than the observed one. Our main-sequence models produce only about a third of the required dissipation (Q'_*r_~2-5x10^5^). Therefore, the observed orbital decay can only be explained by a slightly larger or more evolved host, resembling the case for WASP-12. Our findings highlight the need for further stellar modelling and improvement in our current understanding of tidal dissipation mechanisms driving orbital decay in close-in exoplanetary systems.2025MNRAS.541..714Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/541/714CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/MNRAS/399/287 : Transiting planetary system WASP-4 (Southworth+, 2009)J/ApJ/733/127 : Four transits of WASP-4b (Sanchis-Ojeda+, 2011)J/MNRAS/490/4230 : Transiting planet WASP-4b (Southworth+, 2019)J/ApJ/893/L29 : WASP-4 RVs + hot Jupiter predicted period changesJ/AJ/163/281 : Radial velocity, transit + occultation of WASP-4J/A+A/669/A124 : KELT-9 b, KELT-16 b, WASP-4 b and HD 97658 (Harre+, 2023)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/541/714https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/541/714http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/541/714https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/541/714https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/541/714http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/541/714GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/MNRAS/541/714/tablea1Mid-transit times used in this studyJustJustification of elimination (see paper for details)meta.notecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateObserved date (UT)'Y:M:D'time.epochnullableEpoch[1626/3045] Mid-transit timefromEXOFAST (BJD_TDB)dtime.epochintTcExofast[2458681.71/2460580.67] Mid-transit timefromEXOFAST (BJD_TDB)dtime.epochdoublee_TcExofast[0.0/0.01] Error of the mid-transit timefromEXOFASTdstat.errordoubleBetaRed noise numbermeta.numberfloatPNRPhoton noise rate in pptinstr.det.noisefloatObserName of the observatorymeta.id;instr.obstycharElim[0/1] Elimination of the data (0:Included, 1:Eliminated)meta.codeintJ/MNRAS/541/714/tablea2Mid-transit times we derived from TESS observationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTcExofast[2458355.18/2460205.96] Mid-transit time from EXOFASTdtime.epochdoublee_TcExofast[0.0/0.01] Error of the mid-transit time from EXOFASTdstat.errordoubleSector[2/69] TESS Sector Numberobs.fieldintPNRPhoton noise rate in pptinstr.det.noisefloatBetaRed noise numbermeta.numberfloatElim[0/1] Elimination of the data (0: Included, 1: Eliminated)meta.codeintJustJustification of elimination (see paper for details)meta.notecharJ/MNRAS/541/714/tablea3Mid-transit times we derived from the light curves in the Exoplanet Transit Database (ETD)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTcExofastMid-transit time from EXOFASTdtime.epochdoublee_TcExofastError of the mid-transit time from EXOFASTdstat.errordoubleTcReportedMid-transit time reported by the observerdtime.epochdoublee_TcReportedError of the mid-transit time reported by the observerdstat.errorfloatBetaRed noise numbermeta.numberfloatPNRPhoton noise rate in pptinstr.det.noisefloatObserverName(s) of the observer(s) as appeared in ETDmeta.id;obs.observercharElimElimination of the data (0: Included, 1: Eliminated)meta.codeintJustJustification of elimination (see paper for details)meta.notecharJ/MNRAS/541/714/tablea4Mid-transit times we derived from literature light curvese_TcExofastError of the mid-transit timedstat.errordoubleTcReportedMid-transit time reported by the observerdtime.epochdoublee_TcReportedError of the mid-transit time reported by the observerdstat.errordoubleBetaRed noise numbermeta.numberfloatPNRPhoton noise rate in pptinstr.det.noisefloatRefLiterature Reference of the mid-transit time (1)meta.ref;time.epochcharElimElimination of the data (0: Included, 1: Eliminated)meta.codeintJustJustification of elimination (see paper for details)meta.notecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTcExofastMid-transit time from EXOFASTdtime.epochdoubleJ/MNRAS/541/714/tablea5Mid-transit times we made use of directly from the literaturerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTcReportedMid-transit time reported by the observerdtime.epochdoublee_TcReportedError of the mid-transit time reported by the observerdstat.errordoubleRefLiterature reference of the mid-transit time (1)meta.ref;time.epochchar