J/AJ/162/265ivo://CDS.VizieR/J/AJ/162/265doi:10.26093/cds/vizier.51620265CDSMacdougall M.G.Petigura E.A.Angelo I.Lubin J.Batalha N.M.,Beard C.Behmard A.Blunt S.Brinkman C.Chontos A.Crossfield I.J.M.,Dai F.Dalba P.A.Dressing C.Fulton B.Giacalone S.Hill M.L.,Howard A.W.Huber D.Isaacson H.Kane S.R.Mayo A.Mocnik T.,Murphy J.M.A.Polanski A.Rice M.Robertson P.Rosenthal L.J.Roy A.,Rubenzahl R.A.Scarsdale N.Turtelboom E.Van Zandt J.Weiss L.M.,Matthews E.Jenkins J.M.Latham D.W.Ricker G.R.Seager S.,Vanderspek R.K.Winn J.N.Brasseur C.E.Doty J.Fausnaugh M.,Guerrero N.Henze C.Lund M.B.Shporer A.2025-05-05T20:07:39Z2022-03-09T07:59:55ZCDS support team

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

cds-question@unistra.frexoplanetsk-starsradial-velocityvisible-astronomyspectroscopyWe report the discovery of HIP-97166b (TOI-1255b), a transiting sub-Neptune on a 10.3day orbit around a K0 dwarf 68pc from Earth. This planet was identified in a systematic search of TESS Objects of Interest for planets with eccentric orbits, based on a mismatch between the observed transit duration and the expected duration for a circular orbit. We confirmed the planetary nature of HIP-97166b with ground-based radial-velocity measurements and measured a mass of M_b_=20{+/-}2M{Earth} along with a radius of R_b_=2.7{+/-}0.1R{Earth} from photometry. We detected an additional nontransiting planetary companion with M_c_sini=10{+/-}2M{Earth} on a 16.8day orbit. While the short transit duration of the inner planet initially suggested a high eccentricity, a joint RV-photometry analysis revealed a high impact parameter b=0.84{+/-}0.03 and a moderate eccentricity. Modeling the dynamics with the condition that the system remain stable over >10^5^ orbits yielded eccentricity constraints e_b_=0.16{+/-}0.03 and e_c_<0.25. The eccentricity we find for planet b is above average for the small population of sub-Neptunes with well-measured eccentricities. We explored the plausible formation pathways of this system, proposing an early instability and merger event to explain the high density of the inner planet at 5.3{+/-}0.9g/cc as well as its moderate eccentricity and proximity to a 5:3 mean-motion resonance.2021AJ....162..265Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/162/265CatalogResearchIsServedByTAP VizieR generic servicerelated-toVII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)I/345 : Gaia DR2 (Gaia Collaboration, 2018)IV/38 : TESS Input Catalog - v8.0 (TIC-8) (Stassun+, 2019)J/ApJ/787/80 : 139 Kepler planets transit time variations (Hadden+, 2014)J/ApJ/790/146 : Planets in Kepler's multi-transiting systems (Fabrycky+, 2014)J/ApJS/210/20 : Small Kepler planets radial velocities (Marcy+, 2014)J/ApJ/825/19 : Mass-radius relationship planets with Rp<4 (Wolfgang+, 2016)J/AJ/153/142 : Radial velocities systems hosting sub-Saturns (Petigura+, 2017)J/AJ/154/107 : California-Kepler Survey (CKS). I. 1305 stars (Petigura+, 2017)J/AJ/154/228 : Properties of transiting planet's host stars (Sandford+, 2017)J/ApJ/844/102 : KIC star parallaxes from asteroseismology/Gaia (Huber+, 2017)J/AJ/155/48 : California-Kepler Survey. V. Masses and radii (Weiss+, 2018)J/AJ/156/18 : APOGEE DR14:Binary comp. of evolved stars (Price-Whelan+, 2018)J/AJ/156/264 : California-Kepler Survey VII. Planet radius gap (Fulton+, 2018)J/AJ/159/235 : Radial Velocity jitters in ~600 planet host stars (Luhn+, 2020)J/AJ/159/280 : Gaia-Kepler stellar properties cat.I. KIC stars (Berger+, 2020)J/ApJS/254/39 : Exoplanet candidates from TESS first 2yr obs (Guerrero+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/162/265https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/162/265http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/162/265https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/162/265https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/162/265http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/162/265GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/AJ/162/265/table1Radial velocity measurementsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObs[2020/2021] Year of the observationtime.epochBJD[2458978/2459316] Barycentric Julian Datedtime.epochdoubleTelTelescope identifier; APF or HIRESmeta.id;instr.telcharRVel[-18.8/19.6] Radial velocitym/sphys.veloc;pos.heliocentricfloate_RVel[0.7/8.1] Uncertainty in RVelm/sstat.error;spect.dopplerVelocfloatSHK[0.11/0.35] S_HK_ activity index (1)meta.code.multipfloate_SHK[0.001/0.002] Uncertainty in SHK (1)stat.errorfloat