J/AJ/161/157ivo://CDS.VizieR/J/AJ/161/157doi:10.26093/cds/vizier.51610157CDSHurt S.A.Quinn S.N.Latham D.W.Vanderburg A.Esquerdo G.A.,Calkins M.L.Berlind P.Angus R.Latham C.A.Zhou G.2022-01-17T12:16:29Z2021-07-05T06:59:53ZCDS support team

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

cds-question@unistra.frexoplanetsa-starsradial-velocityvisible-astronomyspectroscopyWe present an analysis of 1524 spectra of Vega spanning 10yr, in which we search for periodic radial-velocity variations. A signal with a periodicity of 0.676day and a semi-amplitude of ~10m/s is consistent with the rotation period measured over much shorter time spans by previous spectroscopic and spectropolarimetric studies, confirming the presence of surface features on this A0 star. The activity signal appears to evolve on long timescales, which may indicate the presence of failed fossil magnetic fields on Vega. TESS data reveal Vega's photometric rotational modulation for the first time, with a total amplitude of only 10ppm. A comparison of the spectroscopic and photometric amplitudes suggests that the surface features may be dominated by bright plages rather than dark spots. For the shortest orbital periods, transit and radial-velocity injection recovery tests exclude the presence of transiting planets larger than 2R{Earth} and most non- transiting giant planets. At long periods, we combine our radial velocities with direct imaging from the literature to produce detection limits for Vegan planets and brown dwarfs out to distances of 15au. Finally, we detect a candidate radial-velocity signal with a period of 2.43days and a semi-amplitude of 6m/s. If caused by an orbiting companion, its minimum mass would be ~20M{Earth}; because of Vega's pole-on orientation, this would correspond to a Jovian planet if the orbit is aligned with the stellar spin. We discuss the prospects for confirmation of this candidate planet.2021AJ....161..157Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/161/157CatalogResearchIsServedByTAP VizieR generic servicerelated-toI/311 : Hipparcos, the New Reduction (van Leeuwen, 2007)J/AJ/124/1144 : Orbits of 171 single-lined spectro. binaries (Latham, 2002)J/PASP/122/162 : Direct imaging of exoplanets (Beichman+, 2010)J/ApJ/720/1118 : i-band photometry of HAT-P-16 (Buchhave+, 2010)J/A+A/531/L2 : Images of Vega at 1.3mm (Pietu+, 2011)J/ApJ/757/18 : RVel for 16 hot Jupiter host stars (Albrecht+, 2012)J/other/Sci/350.64 : 51 Eri b near-infrared spectrum (Macintosh+, 2015)J/AJ/152/136 : Follow-up photometry and spectroscopy of KELT-17 (Zhou+, 2016)J/MNRAS/474/2094 : Inferring proba. stellar rotation periods (Angus+, 2018)J/A+A/618/A20 : Limb-darkening for TESS, Kepler, Corot, MOST (Claret, 2018)J/ApJ/860/109 : Keck HIRES obs. 245 subgiants (retired Astars) (Ghezzi+, 2018)J/A+A/632/A69 : CaII transmission spectrum of WASP-33b and KELT-9b (Yan+,2019)J/AJ/158/141 : Differential photo. & RVs of HAT-P-69 & HAT-P-70 (Zhou+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/161/157https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/161/157http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/161/157https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/161/157https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/161/157http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/161/157GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/AJ/161/157/table2TRES Radial Velocities of VegarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[0/1523] Internal index numbermeta.id;meta.mainintBJD[2454995/2458928] Barycentric Julian Datedtime.epochdoubleRVel[-162/118] Radial velocitym/sphys.veloc;pos.heliocentricfloate_RVel[10.5/144] Uncertainty in RVelm/sstat.error;spect.dopplerVelocfloat