J/A+A/693/A32ivo://CDS.VizieR/J/A+A/693/A32doi:10.26093/cds/vizier.36930032CDSNardiello D.Akana Murphy J.M.Spinelli R.Baratella M.Desidera S.,Nascimbeni V.Malavolta L.Biazzo K.Maggio A.Locci D.Benatti S.,Batalha N.M.D'Orazi V.Borsato L.Piotto G.Oelkers R.J.Mallonn M.,Sozzetti A.Bedin L.R.Mantovan G.Zingales T.Affer L.Bignamini A.,Bonomo A.S.Cabona L.Collins K.A.Damasso M.Filomeno S.Ghedina A.,Harutyunyan A.Lanza A.F.Mancini L.Rainer M.Scandariato G.,Schwarz R.P.Sefako R.Srdoc G.2026-01-29T20:00:55Z2024-12-24T09:38:09ZCDS support team

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

cds-question@unistra.frmultiple-starsexoplanetsradial-velocityphotometryvisible-astronomySmall-sized (<4R_{Earth}_) exoplanets in tight orbits around young stars (10-1000Myr) give us the opportunity to investigate the mechanisms that led to their formation, the evolution of their physical and orbital properties and, especially, of their atmospheres. Thanks to the all-sky survey carried out by the TESS spacecraft, many of these exoplanets have been discovered and have subsequently been characterized with dedicated follow-up observations. In the context of a collaboration among the Global Architecture of Planetary Systems (GAPS) team, the TESS-Keck Survey (TKS) team and, the California Planet Search (CPS) team, we measured with a high level of precision the mass and the radius of TOI-1430 b, a young (~700Myr) exoplanet with an escaping He atmosphere orbiting the K-dwarf star HD 235088 (TOI-1430). By adopting appropriate stellar parameters, which were measured in this work, we were able to simultaneously model the signals due to strong stellar activity and the transiting planet TOI-1430 b in both photometric and spectroscopic series. This allowed us to measure both the radius and mass (and consequently the density) of the planet with high precision, and reconstruct the evolution of its atmosphere. TOI-1430 is an active K-dwarf star born 700+/-150Myr ago and rotates in Prot~12-days. This star hosts a mini-Neptune whose orbital period is Pb=7.434133+/-0.000004-days. Thanks to long-term photometric and spectroscopic monitoring of this target performed with TESS, HARPS-N, HIRES, and APF, we estimated a radius Rb=1.98+/-0.07R_{Earth}_, a mass Mb=4.2+/-0.8M_{Earth}_, and thus a planetary density rhob=0.5+/-0.1rho_{Earth}_. TOI-1430 b is hence a low-density mini-Neptune with an extended atmosphere, at the edge of the radius gap. Because this planet is known to have an evaporating atmosphere of He, we reconstructed its atmospheric history. Our analysis supports the scenario in which, shortly after its birth, TOI-1430 b may have been super-puffy, with a radius 5X-13X and a mass 1.5X-2X that of today; in ~200Myr from now, TOI-1430 b should lose its envelope, showing its Earth-size core. We also looked for signals from a second planet in the spectroscopic/photometric series, without detecting any.2025A&A...693A..32Nhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/693/A32CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/693/A32https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/693/A32http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/693/A32https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/693/A32https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/693/A32http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/693/A32GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/A+A/693/A32/tablea1HARPS-N spectroscopic seriesBISCCF bisector spanm/sphys.velocfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBJDBarycentric TESS Julian Date, TDB (BJD-2457000)dtime.epochdoubleRVRadial Velocitym/sphys.veloc;pos.heliocentricdoublee_RVError on the radial velocitym/sstat.errorfloatlogRHKCa II H&K lines (log(R'_HK_))phot.flux;arith.ratiofloate_logRHKError on Ca II H&K lines (log(R'_HK_))stat.errorfloatHalphaChromospheric H-alpha indexspect.indexdoublee_HalphaError on chromospheric H-alpha indexstat.error;spect.linedoubleJ/A+A/693/A32/tablea2HIRES spectroscopic seriesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBJDBarycentric TESS Julian Date, TDB (BJD-2457000)dtime.epochdoubleRVRadial Velocitym/sphys.veloc;pos.heliocentricfloate_RVError on the radial velocitym/sstat.errorfloatlogRHKCa II H&K lines (log(R'_HK_))phot.flux;arith.ratiofloate_logRHKError on Ca II H&K lines (log(R'_HK_))stat.errorfloatJ/A+A/693/A32/tablea3APF spectroscopic seriesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBJDBarycentric TESS Julian Date, TDB (BJD-2457000)dtime.epochdoubleRVRadial Velocitym/sphys.veloc;pos.heliocentricfloate_RVError on the radial velocitym/sstat.errorfloatlogRHKCa II H&K lines (log(R'_HK_))phot.flux;arith.ratiofloate_logRHKError on Ca II H&K lines (log(R'_HK_))stat.errorfloat