J/A+A/707/A93ivo://CDS.VizieR/J/A+A/707/A93CDSHartogh C.Jeffers S.V.Dreizler S.Barnes J.R.Haswell C.A.,Liebing F.Collier Cameron A.Gorrini P.Del Sordo F.Cortes-Zuleta P.2026-04-02T06:28:33Z2026-03-04T07:39:12ZCDS support team

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

cds-question@unistra.frmultiple-starsexoplanetsradial-velocityvisible-astronomyGJ 877 is a bright M dwarf in the solar neighborhood with two currently reported nontransiting exoplanets with periods of 9d and 21d, along with an additional unconfirmed signal at 50d. We reanalyzed the system with 101 new HARPS and 12 new ESPRESSO radial velocities (RVs) secured with a cadence to confirm or refute the origin of the 50 d signal. To do so, we searched for signals related to stellar activity in photometric data and spectroscopic indicators. We modeled the stellar activity in the RVs with Gaussian processes (GPs). With the Bayesian analysis, we confirmed a four-planet model, including the two previously known planets at periods of 9.2619+/-0.0005d and 21.784+/-0.004d, as well as two newly confirmed exoplanets: an Earth-mass planet, with a 4.42490+/-0.00014d period and a sub-meter-per-second amplitude, and a super-Earth with a 50.77+/-0.05d period located in the habitable zone (HZ). This super-Earth is the second closest planet in the HZ, after Proxima Cen b. We found an additional signal in a 2:1 resonance with the 4.4d planet at 2.21661+/-0.00010d with an amplitude of 0.37+/-0.09m/s, which could be related to an additional planet. However, other explanations of its origin are also plausible. This signal remains a candidate, as further investigation is required to confirm its true nature. If the signal is caused by a planet, its minimum mass would be half that of Earth. We measured the stellar rotation period with the characteristic periodic timescale of the GP. We found a period of 38.7+/-0.5d, which is consistent with the rotation period determined from photometry and other activity indices.2026A&A...707A..93Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/707/A93CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/707/A93https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/707/A93http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/707/A93https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/707/A93https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/707/A93http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/707/A93GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/A+A/707/A93/tablee1Radial velocity ESPRESSOrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBJDBarycentric Julian Datedtime.epochdoubleRVRadial velocitym/sphys.veloc;pos.heliocentricdoublee_RVUncertainty on RVm/sstat.errordoubleJ/A+A/707/A93/tablee2Radial velocity and activity indicators HARPSrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBJDBarycentric Julian Datedtime.epochdoubleRVRadial velocity servalm/sphys.veloc;pos.heliocentricdoublee_RVRadial velocity error servalm/sstat.errordoubleDRSDRS radial velocitym/sphys.veloc;pos.heliocentricdoublee_DRSDRS radial velocity errorm/sstat.errordoubleFWHMFull width half maximum of CCFkm/sspect.line.widthdoubleBISBisector span of CCFkm/sphys.velocdoubledLWDifferential line widthspect.line.widthdoublee_dLWDifferential line width errorstat.errordoublecrxChromatic indexm/sspect.indexdoublee_crxChromatic index errorm/sstat.errordoubleHalphaHalpha indexspect.indexdoublee_HalphaHalpha index errorstat.error;spect.linedoubleNaD1NaD1 indexspect.indexdoublee_NaD1NaD1 index errorstat.errordoubleNaD2NaD2 indexspect.indexdoublee_NaD2NaD2 index errorstat.errordoubleDriftCARACAL Driftm/sstat.paramdoubleSASecular accelerationm/sphys.accelerationdouble