J/MNRAS/430/2932ivo://CDS.VizieR/J/MNRAS/430/2932doi:10.26093/cds/vizier.74302932CDSMancini L.Nikolov N.Southworth J.Chen G.Fortney J.J.,Tregloan-Reed J.Ciceri S.Van Boekel R.Henning T.2024-07-21T20:14:13Z2013-06-18T13:08:01ZCDS support team

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

cds-question@unistra.frmultiple-starssolar-system-planetsvisible-astronomysloan-photometryWe present ground-based broad-band photometry of two transits in the WASP-44 planetary system obtained simultaneously through four optical (Sloan g', r', i', z') and three near-infrared (NIR; J, H, K) filters. We achieved low scatters of 1-2mmag per observation in the optical bands with a cadence of roughly 48s, but the NIR-band light curves present much greater scatter. We also observed another transit of WASP-44 b by using a Gunn r filter and telescope defocussing, with a scatter of 0.37 mmag per point and an observing cadence around 135 s. We used these data to improve measurements of the time of mid- transit and the physical properties of the system. In particular, we improved the radius measurements of the star and planet by factors of 3 and 4, respectively. We find that the radius of WASP-44 b is 1.002+/-0.033+/-0.018RJup (statistical and systematic errors, respectively), which is slightly smaller than previously thought and differs from that expected for a core-free planet. In addition, with the help of a synthetic spectrum, we investigated the theoretically predicted variation of the planetary radius as a function of wavelength, covering the range 370-2440nm. We can rule out extreme variations at optical wavelengths, but unfortunately our data are not precise enough (especially in the NIR bands) to differentiate between the theoretical spectrum and a radius which does not change with wavelength. The resulting measurements of transit mid-points were fitted with a straight line to obtain a new orbital ephemeris: T0=BJD(TDB)2455434.37642(37)+2.4238133(23)xE, where E is the number of orbital cycles after the reference epoch [the mid-point of the first transit observed by Anderson et al. (2012, Cat. J/MNRAS/422/1988)] and quantities in parentheses denote the uncertainty in the final digit of the preceding number.2013MNRAS.430.2932Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/430/2932CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/MNRAS/408/1680 : Transiting planetary system WASP-2 (Southworth+, 2010)J/MNRAS/396/1023 : Transiting planetary system WASP-5 (Southworth+, 2009)J/MNRAS/399/287 : Transiting planetary system WASP-4 (Southworth+, 2009)J/A+A/527/A8 : Transiting planetary system WASP-7 (Southworth+, 2011)J/ApJ/707/167 : Transiting planetary system WASP-18 (Southworth+, 2009)J/MNRAS/426/1338 : Transiting planetary system WASP-17 (Southworth+, 2012)J/A+A/551/A11 : Transiting planetary system HAT-P-8 (Mancini+, 2013)J/MNRAS/422/3099 : Transiting planetary system HAT-P-5 (Southworth+, 2012)J/MNRAS/420/2580 : Transiting planetary system HAT-P-13 (Southworth+, 2012)J/A+A/549/A10 : Transiting planetary system GJ1214 (Harpsoe+, 2013)J/MNRAS/422/1988 : Transiting exoplanets WASP-44b, 45b & 46b (Anderson+, 2012)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/430/2932https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/430/2932http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/430/2932https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/430/2932https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/430/2932http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/430/2932GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/MNRAS/430/2932/table1Log of the observations presented in this workrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTr[1/3] Transit number (1)meta.idintLCShow the light curves for this transitmeta.ref.urlcharObsObservation datestime.epoch;obsnullableEndEnd of observation time (UT)time.endnullableNobs[156/631] Number of observationsmeta.numberintExpTimeExposure timestime.duration;obs.exposureintFiltFilter name (J, H, K, Gunn r, Sloan g', r', i', z')meta.notecharAirM1Airmass at startobs.airMassfloatAirM2Airmass at mid-observation or endobs.airMassfloatAirM3? Airmass at endobs.airMassfloatnullableMoon[31/80] Fractional illumination of the Moon at the mid-point of the transit%pos.lunar.occultintAp*Radius of the software aperture for the starpixinstr.fovfloatApIRadius of the software aperture for the inner skypixinstr.fovfloatApORadius of the software aperture for the outer skypixinstr.fovfloatScatMagnitude scattermagstat.errordoublebeta{beta} factor used to inflate the error bars, in order to assess red noise (see section 3)stat.fit.paramfloatFileNameName of the light curve file in subdirectory photmeta.id;meta.filechar