J/AJ/164/21ivo://CDS.VizieR/J/AJ/164/21doi:10.26093/cds/vizier.51640021CDSSmith A.M.S.Csizmadia S.2023-07-03T13:18:57Z2022-11-04T07:15:06ZCDS support team

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

cds-question@unistra.frk-starsexoplanetsvisible-astronomynarrow-band-photometryK2-139b is a warm Jupiter with an orbital period of 28.4days, but only three transits of this system have previously been observed-in the long-cadence mode of K2-limiting the precision with which the orbital period can be determined and future transits predicted. We report photometric observations of four transits of K2-139b with ESA's CHaracterising ExOPlanet Satellite (CHEOPS), conducted with the goal of measuring the orbital obliquity via spot-crossing events. We jointly fit these CHEOPS data alongside the three previously-published transits from the K2 mission, considerably increasing the precision of the ephemeris of K2-139b. The transit times for this system can now be predicted for the next decade with a 1{sigma} precision less than 10 minutes, compared to over one hour previously, allowing the efficient scheduling of observations with Ariel. We detect no significant deviation from a linear ephemeris, allowing us to exclude the presence of a massive outer planet orbiting with a period less than 150 days, or a brown dwarf with a period less than one year. We also determine the scaled semimajor axis, the impact parameter, and the stellar limb darkening with improved precision. This is driven by the shorter cadence of the CHEOPS observations compared to that of K2, and validates the subexposure technique used for analyzing long-cadence photometry. Finally, we note that the stellar spot configuration has changed from the epoch of the K2 observations; unlike the K2 transits, we detect no evidence of spot-crossing events in the CHEOPS data.2022AJ....164...21Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/164/21CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/643/A94 : CHEOPS WASP-189 b transit light curve (Lendl+, 2020)J/A+A/646/A157 : HD 108236 CHEOPS light curves (Bonfanti+, 2021)J/A+A/653/A173 : CHEOPS 55 Cnc light curve (Morris+, 2021)J/MNRAS/506/3810 : 7 transiting exoplanets CHEOPS light curves (Borsato+, 2021)J/other/ExA/51.109 : Transit KELT-11b observed by CHEOPS (Benz+, 2021)J/other/NatAs/5.775 : nu2 Lupi CHEOPS light curves (Delrez+, 2021)J/other/RNAAS/5.13 : CHEOPS limb & gravity-darkening coefficient (Claret, 2021)J/A+A/657/A52 : CHEOPS transit light curves of WASP-103 b (Barros+, 2022)J/A+A/659/A74 : CHEOPS phase curve of WASP-189 b (Deline+, 2022)J/A+A/659/L7 : AU Mic b and c transits with CHEOPS (Szabo+, 2022)J/A+A/664/L15 : Quaoar stellar occultation observed by CHEOPS (Morgado+, 2022)J/MNRAS/511/4551 : TOI-561 CHEOPS light curves (Lacedelli+, 2022)J/MNRAS/514/77 : CHEOPS Early Science observations (Maxted+, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/164/21https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/164/21http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/164/21https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/164/21https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/164/21http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/164/21GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/AJ/164/21/table2CHEOPS light curve of K2-139recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBJD[9028/9398] Barycentric Julian Date at TDB; BJD-2450000dtime.epochdoubleFlux[0.97/1.02] Relative fluxphot.flux;arith.ratiodoublee_Flux[0.0007/0.0009] Error on Fluxstat.error;phot.fluxdoubleRoll[19.3/344] Spacecraft roll angledeginstr.offsetfloat