J/A+A/661/A141ivo://CDS.VizieR/J/A+A/661/A141doi:10.26093/cds/vizier.36610141CDSLeleu A.Delisle J.-B.Mardling R.Udry S.Chatel G.Alibert Y.,Eggenberger P.2022-10-14T13:57:07Z2022-05-31T12:43:39ZCDS support team

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

cds-question@unistra.frmultiple-starsexoplanetsTransit timing variations (TTVs) can provide useful information for systems observed in this way, putting constraints on the masses and eccentricities of the observed planets, and in some cases even revealing the existence of non- transiting companions. However, TTVs can also prevent the detection of small planets in transit surveys, or bias the recovered planetary and transit parameters. Here we show that Kepler-1972 c, initially the "not transit-like" false positive KOI-3184.02, is an Earth-sized planet whose orbit is perturbed by Kepler-1972 b (initially KOI-3184.01). The pair is locked in a 3:2 mean- motion resonance, each planet displaying TTVs of more than 6h of amplitude over the duration of the Kepler mission. The two planets have similar masses m_b_/m_c_=0.956_-0.051_^+0.056^ and radii R_b_=0.802_-0.041_^+0.042^R_{Earth}_, R_c_=0.868_-0.050_^+0.051^R_{Earth}_, and the whole system, including the inner candidate KOI-3184.03, appears to be coplanar. Despite the faintness of the signals (signal-to-noise ratio (S/N) of 1.35 for each transit of Kepler-1972 b and 1.10 for Kepler-1972 c), we recovered the transits of the planets using the RIVERS method, which is based on recognition of the tracks of planets in river diagrams using machine learning, and a photo-dynamic fit of the light curve. Recovering the correct ephemerides of the planets is essential to obtaining a complete picture of the observed planetary systems. In particular, we show that in Kepler-1972, not taking into account planet-planet interactions yields an error of ~30% on the radii of planets b and c, in addition to generating in-transit scatter, which is why KOI3184.02 was mistaken for a false positive. Alleviating this bias is essential for an unbiased view of Kepler systems,some of the TESS stars, and the upcoming PLATO mission.2022A&A...661A.141Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/661/A141CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/661/A141https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/661/A141http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/661/A141https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/661/A141https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/661/A141http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/661/A141GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/661/A141/timingsbTransit timings of Kepler-1972 brecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDate[111.9/1598.78] Median transit date, BJD-2454833.0dtime.epoch;stat.mediandoubleb_Date[111.89/1598.77] Date 0.15865 quantile, BJD-2454833.0dtime.epochdoubleB_Date[111.91/1598.79] Date 0.84135 quantile, BJD-2454833.0dtime.epochdoubleJ/A+A/661/A141/timingscTransit timings of Kepler-1972 crecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDate[111.9/1598.78] Median transit date, BJD-2454833.0dtime.epoch;stat.mediandoubleb_Date[111.89/1598.77] Date 0.15865 quantile, BJD-2454833.0dtime.epochdoubleB_Date[111.91/1598.79] Date 0.84135 quantile, BJD-2454833.0dtime.epochdoubleJ/A+A/661/A141/samplesSamples of the photodynamic fit of Kepler-1972recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambda1[3.24/59.44] Mean longitude for planet bdegpos.galactic.londoubleP1[7.54/7.55] Orbital period for planet bdtime.perioddoubleecw1[-0.3/0.2] ecc_b_*cos(long of pericenter b)src.orbital.eccentricitydoubleesw1[-0.16/0.22] ecc_b_*sin(long of pericenter b)src.orbital.eccentricitydoublelogmu[-5.45/-4.72] log10((mb+mc)/m*) magnitude ratiophot.magdoublelambda2[140.23/187.41] Mean longitude for planet cdegpos.galactic.londoubleP2[11.32/11.34] Orbital period for planet cdtime.perioddoubleecw2[-0.27/0.14] ecc_c_*cos(long of pericenter c)src.orbital.eccentricitydoubleesw2[-0.19/0.14] ecc_c_*sin(long of pericenter c)src.orbital.eccentricitydoublelogdelta[0.44/0.54] mb/(mb+mc) magnitude ratiophot.magdoubleR1[0.0/0.01] Radius of planet b in R* unitsphys.size.radius;arith.ratiodoubleR2[0.0/0.01] Radius of planet c in R* unitsphys.size.radius;arith.ratiodoubleImpact1[0.0/0.72] Impact parameter for planet bsrc.impactParamdoubleImpact2[0.72/0.9] Impact parameter for planet csrc.impactParamdoublet0-03[134.81/134.87] Time of transit for 03 (BJD-2454833.0)dtime.epochdoubleP03[4.02/4.03] Period for 03dtime.perioddoubleR03[0.0/0.01] Radius for 03 in R* unitsphys.size.radius;arith.ratiodoubleImpact03[0.0/0.64] Impact parameter for 03src.impactParamdoublelogsigjitt0[-4.41/-4.38] Light curve jitterstat.stdev;phys.velocdoublelogsigGP0[-9.98/-6.16] Gaussian process amplitudephys.veloc;src.orbitaldoublelogtauGP0[0.01/3.0] Gaussian process timescalelog(d)time.scaledoublerho*[0.31/0.56] Stellar density in Sun density unitsSunsrc.densitydoublelimbdarku1[0.37/0.54] Limb darkening coefficient u1phot.limbDarkdoublelimbdarku2[0.15/0.34] Limb darkening coefficient u2phot.limbDarkdouble