J/ApJ/746/36ivo://CDS.VizieR/J/ApJ/746/36doi:10.26093/cds/vizier.17460036CDSGaidos E.Fischer D.A.Mann A.W.Lepine S.2013-10-12T17:42:52Z2013-09-26T07:19:08ZCDS support team

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

cds-question@unistra.frradial-velocitysolar-system-planetsWe constrain the densities of Earth- to Neptune-size planets around very cool (T_e_=3660-4660K) Kepler stars by comparing 1202 Keck/HIRES radial velocity measurements of 150 nearby stars to a model based on Kepler candidate planet radii and a power-law mass-radius relation. Our analysis is based on the presumption that the planet populations around the two sets of stars are the same. The model can reproduce the observed distribution of radial velocity variation over a range of parameter values, but, for the expected level of Doppler systematic error, the highest Kolmogorov-Smirnov probabilities occur for a power-law index {alpha}{approx}4, indicating that rocky-metal planets dominate the planet population in this size range. A single population of gas-rich, low-density planets with {alpha}=2 is ruled out unless our Doppler errors are >=5m/s, i.e., much larger than expected based on observations and stellar chromospheric emission. If small planets are a mix of {gamma} rocky planets ({alpha}=3.85) and 1-{gamma} gas-rich planets ({alpha}=2), then {gamma}>0.5 unless Doppler errors are >=4m/s. Our comparison also suggests that Kepler's detection efficiency relative to ideal calculations is less than unity. One possible source of incompleteness is target stars that are misclassified subgiants or giants, for which the transits of small planets would be impossible to detect. Our results are robust to systematic effects, and plausible errors in the estimated radii of Kepler stars have only moderate impact.2012ApJ...746...36Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/746/36CatalogResearchIsServedByTAP VizieR generic servicerelated-toV/133 : Kepler Input Catalog (Kepler Mission Team, 2009)I/298 : LSPM-North Catalog (Lepine+ 2005)J/AJ/142/112 : KIC photometric calibration (Brown+, 2011)J/ApJ/736/19 : Kepler planetary candidates. II. (Borucki+, 2011)J/AJ/142/138 : All-sky catalog of bright M dwarfs (Lepine+, 2011)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/746/36https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/746/36http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/746/36https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/746/36https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/746/36http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/746/36GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/ApJ/746/36/table1Radial velocity statistics of 150 stars with T_e_=3660-4660K in the M2K surveyrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/150] Stellar index numbermeta.id;meta.mainintNm[3/68] Number of measurementsmeta.numberintStDeV[0.53/13331] Velocity standard deviationm/sstat.stdevdoubleErr[0.1/8.41] Formal errorm/sstat.errorfloat