J/ApJ/893/L29ivo://CDS.VizieR/J/ApJ/893/L29doi:10.26093/cds/vizier.18939029CDSBouma L.G.Winn J.N.Howard A.W.Howell S.B.Isaacson H.Knutson H.,Matson R.A.2022-09-13T11:36:36Z2021-10-13T07:43:59ZCDS support team

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

cds-question@unistra.frexoplanetsradial-velocityvisible-astronomyThe orbital period of the hot Jupiter WASP-4b appears to be decreasing at a rate of -8.64+/-1.26ms/yr, based on transit-timing measurements spanning 12yr. Proposed explanations for the period change include tidal orbital decay, apsidal precession, and acceleration of the system along the line of sight. To investigate further, we performed new radial-velocity measurements and speckle imaging of WASP-4. The radial-velocity data show that the system is accelerating toward the Sun at a rate of -0.0422+/-0.0028m/s/day. The associated Doppler effect should cause the apparent period to shrink at a rate of -5.94+/-0.39ms/yr, comparable to the observed rate. Thus, the observed change in the transit period is mostly or entirely produced by the line-of-sight acceleration of the system. This acceleration is probably caused by a wide-orbiting companion of mass 10-300M_Jup_ and orbital distance 10-100au, based on the magnitude of the radial-velocity trend and the nondetection of any companion in the speckle images. We expect that the orbital periods of one out of three hot Jupiters will change at rates similar to WASP-4b, based on the hot-Jupiter companion statistics of Knutson et al. Continued radial-velocity monitoring of hot Jupiters is therefore essential to distinguish the effects of tidal orbital decay or apsidal precession from line-of-sight acceleration.2020ApJ...893L..29Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/893/L29CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/345 : Gaia DR2 (Gaia Collaboration, 2018)J/ApJS/152/261 : Chromospheric Ca II emission in nearby stars (Wright+, 2004)J/MNRAS/399/287 : Transiting planetary system WASP-4 (Southworth+, 2009)J/ApJ/692/L9 : Tidal evolution of transiting exoplanets (Levrard+, 2009)J/AJ/137/3826 : Two transits of the giant planet WASP-4b (Winn+, 2009)J/ApJ/696/1950 : Sloan iz light curves of HAT-P-10 (Bakos+, 2009)J/A+A/524/A25 : Radial Velocities on 6 exoplanet host stars (Triaud+, 2010)J/ApJ/733/127 : Four transits of WASP-4b (Sanchis-Ojeda+, 2011)J/MNRAS/414/1278 : Eccentricities of transiting planets (Pont+, 2011)J/AJ/142/19 : Speckle observations of KOI (Howell+, 2011)J/A+A/530/A5 : WASP-4b thermal emission, Ks-band (Caceres+, 2011)J/A+A/539/A159 : WASP-4b transit griz light curves (Nikolov+, 2012)J/ApJ/785/126 : HIRES radial velocity measurements (Knutson+, 2014)J/ApJ/800/22 : Radial velocities of long-period planets (Feng+, 2015)J/ApJ/806/248 : AO imaging of KOIs with gas giant planets (Wang+, 2015)J/A+A/588/L6 : WASP-12 transit light curves (Maciejewski+ 2016)J/ApJ/821/89 : 12yrs of RVel obs. of exoplanet systems (Bryan+, 2016)J/AJ/152/8 : Impact of stellar multiplicity on planets I. (Kraus+, 2016)J/A+A/602/A107 : 231 transiting planets eccentricity and mass (Bonomo+, 2017)J/AJ/154/4 : Times of transits and occultations of WASP-12b (Patra+, 2017)J/AJ/155/165 : Dissipation in exoplanet hosts (Penev+, 2018)J/AJ/155/255 : RVel and activity measurements of HAT-P-11 (Yee+, 2018)J/AJ/156/18 : Binary companions of evolved stars (Price-Whelan+, 2018)J/AJ/156/216 : Differential photometry & RVs of HATS-59 (Sarkis+, 2018)J/AcA/68/371 : WASP and KELT planet transits (Maciejewski+, 2018)J/AJ/157/52 : Radial velocity obs. in super-Earth systems (Bryan+, 2019)J/AJ/157/217 : Transit times of 5 hot Jupiter WASP exoplanets (Bouma+, 2019)J/AJ/158/190 : Astrometry of main sequence hot Jupiter hosts (Hamer+, 2019)J/MNRAS/490/4230 : Transiting planet WASP-4b (Southworth+, 2019)J/MNRAS/490/5088 : Stellar companions of exoplanet host stars (Mugrauer, 2019)J/AJ/159/19 : SOAR TESS survey. I. (Ziegler+, 2020)J/ApJ/888/L5 : Transits, occultation times and RVs of WASP-12b (Yee+, 2020)J/A+A/636/A74 : HARPS radial velocity database (Trifonov+, 2020)J/AJ/159/150 : Transit times of 11 hot Jupiters (Patra+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/893/L29https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/893/L29http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/893/L29https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/893/L29https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/893/L29http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/893/L29GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/893/L29/table5 (Predicted hot Jupiter period changes from linear radial velocity trends reported by Knutson+ 2014, J/ApJ/785/126)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/893/L29/table5?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/893/L29/table5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/893/L29/table5?GETtext/xml+votable180.050000true245.151491441.04808580.0055555555555555566/876 1275 2532 2551 2711 3344 6017 6181 6349 6539 6638 7036 7208 8197 8825 9173 9459 9482 9524 9811 10654 12424 12862 13143 13439 13569 13680 14825 14886 15129 15143 16432 20339 22001 22505 24409 25132 26062 28548 31641 32564 32749 35210 36142 38452 42936 43847 44648 46437 47476https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/893/L29?format=asciiOpticaldefaultJ/ApJ/893/L29/table5Predicted hot Jupiter period changes from linear radial velocity trends reported by Knutson+ 2014, J/ApJ/785/126recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNamePlanet namemeta.id;meta.mainchardRV/dt[-0.097/0.08] Measured d(RV)/dtm.s**-1.yr**-1arith.rate;phys.velocdoubleE_dRV/dt[0/0.058] Upper 84-50 uncertainty in dRV/dtm.s**-1.yr**-1stat.error;stat.maxdoublee_dRV/dt[0/0.058] Lower 50-16 uncertainty in dRV/dtm.s**-1.yr**-1stat.errordoublePer[0.78/10.9] Planet orbital period from NASA's Exoplanet Archivedtime.perioddoubledP/dt[-55.63/40.76] Doppler predicted dP/dtms/yrarith.rate;time.periodfloatE_dP/dt[0/41.96] Upper 84-50 uncertainty in dP/dtms/yrstat.error;stat.maxfloatSimbadNameSimbad column added by the CDSmeta.idcharnullablee_dP/dt[0/41.96] Lower 50-16 uncertainty in dP/dtms/yrstat.errorfloatSig[0/1] Is d(RV)/dt >3sigma significant?meta.codeintCommCommentmeta.notechar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainJ/ApJ/893/L29/table1WASP-4b transit timesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBJDTransit mid-time, t_tra_, in BJD TDBdtime.epochdoublee_BJD[5e-05/0.001] The 1{sigma} uncertainty in BJDdstat.errordoubleEpoch[-1354/1848] Transit numbermeta.idintRefWho first processed the light-curves (1)meta.bibcharr_BJDProvence of transit mid-time (1)meta.ref;pos.framecharJ/ApJ/893/L29/table2WASP-4 radial velocitiesTelInstrument namemeta.id;instrcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBJDTime in BJD TDB; BJD-2450000dtime.epochdoubleRV[-299/264] Mean subtracted radial velocity per instrumentm/sphys.veloc;pos.heliocentricdoublee_RV[1.7/25.4] Uncertainty in RVm/sstat.errordoubleSind[0.17/0.26]? Chromospheric S-index; blank if NaNspect.indexdoublenullableRefData source (1)meta.bibchar