J/A+A/613/A25ivo://CDS.VizieR/J/A+A/613/A25doi:10.26093/cds/vizier.36130025CDSBonfils X.Astudillo-Defru N.Diaz R.Almenara J.-M.Forveille T.,Bouchy F.Delfosse X.Lovis C.Mayor M.Murgas F.Pepe F.,Santos N. C.Segransan D.Udry S.Wunsche A.2018-05-30T05:07:24Z2018-05-28T07:47:37ZCDS support team

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

cds-question@unistra.frmultiple-starssolar-system-planetsradial-velocityAfter that a new technique combining high-contrast imaging and high-dispersion spectroscopy successfully detected the atmosphere of a giant planet, it soon became contemplated as one of the most promising avenues to study the atmosphere of Earth-size worlds. With the forthcoming ELTs, it shall gain the angular resolution and sensitivity to even detect O2 in the atmosphere of planets orbiting red dwarfs. This is a strong motivation to make the census of planets around cool stars which habitable zones can be resolved by ELTs, i.e. for M dwarfs within ~5-parsecs. In that context, our HARPS survey is already a major contributor to that sample of nearby planets. Here we report on our radial-velocity observations of Ross 128 (Proxima Virginis, GJ447, HIP 57548), a M4 dwarf just 3.4-parsec away from our Sun. We detect it is host of an exo-Earth with a projected mass m*sini=1.35M_{sun}_ and an orbital period of 9.9-days. Ross 128 b receives ~1.38 as much flux as Earth from the Sun and has an equilibrium temperature between 269K (resp. 213K) for an Earth-like (resp. Venus-like) albedo. According to recent studies, it is located at the inner edge of the so called habitable zone. An 80-day long light curve performed by K2 during campaign C01 excludes Ross 128 b is a transiting planet. Together with ASAS photometry and other activity indices, it argues for a long rotational period and a weak activity which, in the context of habitability, gives a high merit to the detection. Today, Ross 128 b is the second closest known exo-Earth after Proxima Centauri b (1.3 parsec) and the closest known temperate planet around a quiet star. At maximum elongation, the planet-star angular separation of 15 milli-arcsec will be resolved by the ELT (>3{lambda}/D) in all optical bands of O_2_.2018A&A...613A..25Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/613/A25CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/613/A25https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/613/A25http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/613/A25https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/613/A25https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/613/A25http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/613/A25GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/613/A25/table4HARPS measured RV for Ross 128recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBJDBarycentric Julian datedtime.epochdoubleRVBarycentric radial velocitykm/sphys.veloc;pos.heliocentricdoublee_RVRadial-velocity uncertaintykm/sstat.errordoubleInst[1/2] Instrument upgrade flagmeta.code.error;instrint