J/A+A/688/A172ivo://CDS.VizieR/J/A+A/688/A172doi:10.26093/cds/vizier/bc-ng/lbhcCDSMaciejewski G.Niedzielski A.Gozdziewski K.Wolszczan A.Villaver E.,Fernandez M.Adamow M.Sierzputowska J.2026-07-03T06:36:06Z2026-01-30T12:56:15ZCDS support team

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

cds-question@unistra.frmultiple-starsexoplanetsradial-velocityvisible-astronomyThe star HD 118203, classified as a K0 subgiant, was known to harbour a transiting hot Jupiter planet on a 6.1-day eccentric orbit. Previous studies also revealed a linear trend in the radial velocity (RV) domain, indicative of a companion on a wide orbit. Such a hierarchical orbital architecture could be helpful in studies of the origins of hot Jupiters. We acquired precise RV measurements over 17yr using the 9.2m Hobby-Eberly Telescope and the 3.6m Telescopio Nazionale Galileo. Combining these observations with space-born photometric time series from the Transiting Exoplanet Survey Satellite, we constructed a two-planetary model for the system. Astrometric observations from HIPPARCOS and Gaia were used to constrain the orbital inclination of the wide-orbit companion and its mass. Numerical simulations were used to investigate the dynamics of the system. The photometric data were searched for additional transit-like flux drops. We found that the additional companion is an 11-Jupiter mass planet orbiting HD 118203 on a 14-yr moderately eccentric orbit, constituting a hierarchical planetary system with the hot Jupiter. Both planets were found to be dynamically decoupled mainly due to the general relativistic apsidal precession of the inner planet, marginalising secular interactions. The orbits of both planets might have a relatively low mutual inclination unless the longitudes of the ascending node differ substantially. This configuration favours the coplanar high-eccentricity migration as a path to the present-day orbital configuration. No other transiting planets with radii down to 2 Earth radii and orbital periods less than 100 days were found in the system.2024A&A...688A.172Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/688/A172CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/613/A47 : Radial velocities of 12 evolved stars (Adamow+, 2018)J/A+A/648/A58 : Radial velocity curves of 4 stars (Niedzielski+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/688/A172https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/688/A172http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/688/A172https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/688/A172https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/688/A172http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/688/A172GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/A+A/688/A172/tablea1Doppler observations from HRSrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTmidMid-exposure time in Barycentric Julian date in Barycentric Dynamical Time (BJD_TDB)dtime.epochdoubleRVRadial velocity measurementkm/sphys.veloc;pos.heliocentricdoublee_RVRadial velocity errorkm/sstat.errordoubleBSBisector spanm/sphys.velocdoubleJ/A+A/688/A172/tablea2Doppler observations from HARPS-NrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTmidMid-exposure time in Barycentric Julian date in Barycentric Dynamical Time (BJD_TDB)dtime.epochdoubleRVRadial velocity measurementkm/sphys.veloc;pos.heliocentricdoublee_RVRadial velocity errorkm/sstat.errordoubleBSBisector spanm/sphys.velocdouble