J/A+A/689/A132ivo://CDS.VizieR/J/A+A/689/A132doi:10.26093/cds/vizier.36890132CDSMallorquin M.Bejar V.J.S.Lodieu N.Zapatero Osorio M.R.Yu H.,Suarez Mascareno A.Damasso M.Sanz-Forcada J.Ribas I.Reiners A.,Quirrenbach A.Amado P.J.Caballero J.A.Aigrain S.Barragan O.,Dreizler S.Fernandez-Martin A.Goffo E.Henning T.Kaminski A.,Klein B.Luque R.Montes D.Morales J.C.Nagel E.Palle E.Reffert S.,Schlecker M.Schweitzer A2024-11-29T20:05:22Z2024-09-10T08:25:13ZCDS support team

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

cds-question@unistra.frmultiple-starsexoplanetsradial-velocityinfrared-astronomyvisible-astronomyUnderstanding planet formation is important in the context of the origin of planetary systems in general and of the Solar System in particular, as well as to predict the likelihood of finding Jupiter, Neptune, and Earth analogues around other stars. We aim to precisely determine the radii and dynamical masses of transiting planets orbiting the young M star AUMic using public photometric and spectroscopic datasets. We performed a joint fit analysis of the TESS and CHEOPS light curves and more than 400 high-resolution spectra collected with several telescopes and instruments. We characterise the stellar activity and physical properties (radius, mass, density) of the transiting planets in the young AUMic system through joint transit and radial velocity fits with Gaussian processes. We determine a radius of R^b^_p_=4.79+/-0.29R_{Earth}_, a mass of M^b^_p_=9.0+/-2.7M_{Earth}_, and a bulk density of {rho}^b^_p_=0.49+/-0.16g/cm^3^ for the innermost transiting planet AUMic b. For the second known transiting planet, AUMic c, we infer a radius of R^c^_p_=2.79+/-0.18R_{Earth}_ , a mass of M^c^_p__=14.5+/-3.4M_{Earth}_ , and a bulk density of {rho}^c^_p_=3.90+/-1.17g/cm^3^. According to theoretical models, AUMic b may harbour an H2 envelope larger than 5% by mass, with a fraction of rock and a fraction of water. AUMic c could be made of rock and/or water and may have an H2 atmosphere comprising at most 5% of its mass. AUMic b has retained most of its atmosphere but might lose it over tens of millions of years due to the strong stellar radiation, while AUMic c likely suers much less photo-evaporation because it lies at a larger separation from its host. Using all the datasets in hand, we determine a 3 upper mass limit of M^[d]^_p_sini=8.6M_{Earth}_ for the AUMic 'd' TTV-candidate. In addition, we do not confirm the recently proposed existence of the planet candidate AUMic 'e' with an orbital period of 33.4 days.We investigated the level of the radial velocity variations and show that it is lower at longer wavelength with smaller changes from one observational campaign to another.2024A&A...689A.132Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/689/A132CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/654/A159 : CHEOPS photometry of Au Mic b transits in 2020 (Szabo+, 2021)J/AJ/162/137 : Minerva-Australis radial velocity of AU Mic (Addison+, 2021)J/A+A/659/L7 : AU Mic b and c transits with CHEOPS (Szabo+, 2022)J/AJ/164/110 : HST/COS far-UV spectra of AU Mic flares (Feinstein+, 2023)J/A+A/682/A170 : AU Mic dynamic spectra of 42 radio observations (Bloot+, 2024)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/689/A132https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/689/A132http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/689/A132https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/689/A132https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/689/A132http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/689/A132GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/A+A/689/A132/tablec1AU Mic CARMENES VIS RV analyzed in this workrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTimeBarycentric Julian datedtime.epochdoubleRVRadial velocitym/sphys.veloc;pos.heliocentricfloate_RVRadial velocity errorm/sstat.errorfloatJ/A+A/689/A132/tablec2AU Mic CARMENES NIR RV analyzed in this workTimeBarycentric Julian datedtime.epochdoubleRVRadial velocitym/sphys.veloc;pos.heliocentricfloate_RVRadial velocity errorm/sstat.errorfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJ/A+A/689/A132/tablec3AU Mic HARPS RV analyzed in this workrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTimeBarycentric Julian datedtime.epochdoubleRVRadial velocitym/sphys.veloc;pos.heliocentricfloate_RVRadial velocity errorm/sstat.errorfloatJ/A+A/689/A132/tablec4AU Mic SPIRou RV analyzed in this workrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTimeBarycentric Julian datedtime.epochdoubleRVRadial velocitym/sphys.veloc;pos.heliocentricfloate_RVRadial velocity errorm/sstat.errorfloat