J/A+A/638/A120ivo://CDS.VizieR/J/A+A/638/A120doi:10.26093/cds/vizier.36380120CDSGratton R.Zurlo A.Le Coroller H.Damasso M.Del Sordo F.Langlois M.,Mesa D.Milli J.Chauvin G.Desidera S.Hagelberg J.Lagadec E.,Vigan A.Boccaletti A.Bonnefoy M.Brandner W.Brown S.Cantalloube F.,Delorme P.D'Orazi V.Feldt M.Galicher R.Henning T.Janson M.,Kervella P.Lagrange A-M.Lazzoni C.Ligi R.Maire A-L.Menard F.,Meyer M.Mugnier L.Potier A.Rickman E.L.Rodet L.Romero C.,Schmidt T.Sissa E.Sozzetti A.Szulagyi J.Wahhaj Z.Antichi J.,Fusco T.Stadler E.Suarez M.Wildi F.2020-09-01T08:52:34Z2020-06-23T08:02:42ZCDS support team

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

cds-question@unistra.frmultiple-starsexoplanetsProxima Centauri is the closest star to the Sun and it is known to host an Earth-like planet in its habitable zone; very recently a second candidate planet was proposed based on radial velocities. At quadrature, the expected projected separation of this new candidate is larger than 1 arcsec, making it a potentially interesting target for direct imaging. While identification of the optical counterpart of this planet is expected to be very difficult, successful identification would allow for a detailed characterization of the closest planetary system. We searched for a counterpart in SPHERE images acquired over four years through the SHINE survey. In order to account for the expected large orbital motion of the planet, we used a method that assumes the circular orbit obtained from radial velocities and exploits the sequence of observations acquired close to quadrature in the orbit. We checked this with a more general approach that considers Keplerian motion, called K-stacker. We did not obtain a clear detection. The best candidate has S/N=6.1 in the combined image. A statistical test suggests that the probability that this detection is due to random fluctuation of noise is <1%, but this result depends on the assumption that the distribution of noise is uniform over the image, a fact that is likely not true. The position of this candidate and the orientation of its orbital plane fit well with observations in the ALMA 12m array image. However, the astrometric signal expected from the orbit of the candidate we detected is 3-sigma away from the astrometric motion of Proxima as measured from early Gaia data. This, together with the unexpectedly high flux associated with our direct imaging detection, means we cannot confirm that our candidate is indeed Proxima c. On the other hand, if confirmed, this would be the first observation in imaging of a planet discovered from radial velocities and the second planet (after Fomalhaut b) of reflecting circumplanetary material. Further confirmation observations should be done as soon as possible.2020A&A...638A.120Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/638/A120CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/534/A133 : Proxima Cen chromospheric emission lines (Fuhrmeister+, 2011)J/AJ/153/93 : MOST photometry of Proxima (Kipping+, 2017)J/A+A/603/A58 : Full spectrum of Proxima Centauri (Ribas+, 2017)J/AJ/155/12 : Photometry of Proxima Centauri observed by BSST (Liu+, 2018)J/A+A/626/A111 : Proxima Cen flare activity temporal changes (Pavlenko+, 2019)J/AJ/157/226 : Photometry of Proxima Centauri from 2006 to 2017 (Feliz+ 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/638/A120https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/638/A120http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/638/A120https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/638/A120https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/638/A120http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/638/A120GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/638/A120/list (List of fits maps)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/638/A120/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/638/A120/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/638/A120/list?GETtext/xml+votable180.050000true217.42895-62.67950.0055555555555555566/41591https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/638/A120?format=asciidefaultJ/A+A/638/A120/listList of fits mapsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension of center (J2000)degpos.eq.ra;meta.mainDEJ2000Declination of center (J2000)degpos.eq.dec;meta.mainNxNumber of pixels along X-axismeta.numberintNyNumber of pixels along Y-axismeta.numberintObs.dateObservation datestime.epoch;obsnullablesizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fitschar