J/A+A/628/A115ivo://CDS.VizieR/J/A+A/628/A115doi:10.26093/cds/vizier.36280115CDSvon Essen C.Stefansson G.Mallonn M.Pursimo T.Djupvik A.A.,Mahadevan S.Kjeldsen H.Freudenthal J.Dreizler S.2019-11-27T09:19:14Z2019-08-14T07:37:47ZCDS support team

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

cds-question@unistra.frmultiple-starsexoplanetsphotometryWe present the characterization of two engineered diffusers mounted on the 2.5-meter Nordic Optical Telescope, located at Roque de Los Muchachos, Spain. To assess the reliability and the efficiency of the diffusers, we carried out several test observations of two photometric standard stars, along with observations of one primary transit observation of TrES-3b in the red (R band), one of CoRoT-1b in the blue (B band), and three secondary eclipses of WASP-12b (V band). The achieved photometric precision is in all cases within the submillimagnitude level for exposures between 25 and 180 seconds. Along with a detailed analysis of the functionality of the diffusers, we add a new transit depth measurement in the blue (B band) to the already observed transmission spectrum of CoRoT-1b, disfavoring a Rayleigh slope. We also report variability of the eclipse depth of WASP-12b in the V band. For the WASP-12b secondary eclipses, we observe a secondary depth deviation of about 5 sigma, and a difference of 6 sigma and 2.5 sigma when compared to the values reported by other authors in a similar wavelength range determined from Hubble Space Telescope data. We further speculate about the potential physical processes or causes responsible for this observed variability.2019A&A...628A.115Vhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/628/A115CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/628/A116 : HAT-P-26 differential transit photometry (von Essen+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/628/A115https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/628/A115http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/628/A115https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/628/A115https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/628/A115http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/628/A115GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/628/A115/lcsEngineered diffuser photometryFilter[BVR] Photometric filter (1)meta.id;instr.filtercharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameTarget of interest (WASP-12, CoRoT-1 or TrES-3)meta.idcharTel[NOT ] Telescopemeta.id;instr.telcharBJDBarycentric Julian Date (TDB)dtime.epochdoubleFluxRawRaw and normalized fluxphot.flux;arith.ratiodoublee_FluxRawUncertainty of raw and normalized fluxstat.errordoubleFluxdetDetrended and normalized fluxphot.flux;arith.ratiodouble