J/ApJ/770/95ivo://CDS.VizieR/J/ApJ/770/95doi:10.26093/cds/vizier.17700095CDSFukui A.Narita N.Kurosaki K.Ikoma M.Yanagisawa K.Kuroda D.,Shimizu Y.Takahashi Y.H.Ohnuki H.Onitsuka M.Hirano T.Suenaga T.,Kawauchi K.Nagayama S.Ohta K.Yoshida M.Kawai N.Izumiura H.2017-07-10T06:37:58Z2015-01-29T14:53:34ZCDS support team

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

cds-question@unistra.frsolar-system-planetsinfrared-photometryvisible-astronomyphotometrymultiple-starsWe present optical (g', R_c_, and I_c_) to near-infrared (J) simultaneous photometric observations for a primary transit of GJ3470b, a Uranus-mass transiting planet around a nearby M dwarf, by using the 50cm MITSuME telescope and the 188cm telescope, both at the Okayama Astrophysical Observatory. From these data, we derive the planetary mass, radius, and density as 14.1 +/-1.3M_{Earth}_, 4.32_-0.10_^+0.21^R_{Earth}_, and 0.94+/-0.12g/cm3, respectively, thus confirming the low density that was reported by Demory et al. (2013ApJ...768..154D) based on the Spitzer/IRAC 4.5{mu}m photometry (0.72_-0.12_^+0.13^g/cm3). Although the planetary radius is about 10% smaller than that reported by Demory et al., this difference does not alter their conclusion that the planet possesses a hydrogen-rich envelope whose mass is approximately 10% of the planetary total mass. On the other hand, we find that the planet-to-star radius ratio (R_p_/R_s_) in the J band (0.07577_-0.00075_^+0.00072^) is smaller than that in the I_c_(0.0802+/-0.0013) and 4.5{mu}m (0.07806_-0.00054_^+0.00052^) bands by 5.8%+/-2.0% and 2.9%+/-1.1%, respectively. A plausible explanation for the differences is that the planetary atmospheric opacity varies with wavelength due to absorption and/or scattering by atmospheric molecules. Although the significance of the observed R_p_/R_s_variations is low, if confirmed, this fact would suggest that GJ3470b does not have a thick cloud layer in the atmosphere. This property would offer a wealth of opportunity for future transmission-spectroscopic observations of this planet to search for certain molecular features, such as H_2_O, CH_4_, and CO, without being prevented by clouds.2013ApJ...770...95Fhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/770/95CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/MNRAS/430/2932 : WASP-44 griz light curves (Mancini+, 2013)J/A+A/559/A33 : Near-IR Spectrophotometry of GJ 3470b (Crossfield+, 2013)J/A+A/559/A32 : Light curves of GJ3470b (Nascimbeni+, 2013)J/A+A/556/A150 : SWEETCat I. Stellar param. for host stars (Santos+, 2013)J/A+A/552/A119 : Planet-star and moon-planet interaction (Saur+, 2013)J/A+A/546/A27 : Radial velocity and photometry for GJ3470 (Bonfils+, 2012)J/A+A/546/A14 : Limb-darkening for CoRoT, Kepler, Spitzer (Claret+, 2012)J/A+A/538/A46 : Transit observations of GJ1214b (de Mooij+, 2012)J/ApJ/757/112 : Stellar diameters. II. K and M-stars (Boyajian+, 2012)J/ApJ/747/35 : HST/WFC3 transit observation of GJ1214b (Berta+, 2012)J/MNRAS/396/1023 : Transiting planetary system WASP-5 (Southworth+, 2009)J/ApJ/683/1076 : Transits of exoplanet XO-3b (Winn+, 2008)J/AJ/106/773 : Mass-luminosity relation (Henry+, 1993)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/770/95https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/770/95http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/770/95https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/770/95https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/770/95http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/770/95GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/ApJ/770/95/table4The J, I_c_, R_c_, and g' light curvesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintFiltFilter used in the observationinstr.setup;obscharBJDBarycentric Julian Date; BJD-2450000 (1)dtime.epochdoubleFlux[0.979/1.011] Relative flux in Filt (2)phot.flux;arith.ratiodoublee_Flux[0.001/0.007] Error in Fluxstat.error;phot.fluxdouble