J/A+A/653/A173ivo://CDS.VizieR/J/A+A/653/A173doi:10.26093/cds/vizier.36530173CDSMorris B.M.Delrez L.Brandeker A.Cameron A.C.Simon A.E.Futyan D.,Olofsson G.Hoyer S.Fortier A.Demory B.-O.Lendl M.Wilson T.G.,Oshagh M.Heng K.Ehrenreich D.Sulis S.Alibert Y.Alonso R.,Anglada Escude G.Barrado D.Barros S.C.C.Baumjohann W.Beck M.,Beck T.Bekkelien A.Benz W.Bergomi M.Billot N.Bonfils X.,Bourrier V.Broeg C.Barczy T.Cabrera J.Charnoz S.Davies M.B.,De Miguel Ferreras D.Deleuil M.Deline A.Demangeon O.D.S.Erikson A.,Floren H.G.Fossati L.Fridlund M.Gandolfi D.Garcia Munoz A.,Gillon M.Guedel M.Guterman P.Isaak K.Kiss L.Laskar J.,Lecavelier des Etangs A.Lieder M.Lovis C.Magrin D.Maxted P.F.L.,Nascimbeni V.Ottensamer R.Pagano I.Palle E.Peter G.Piotto G.,Pizarro Rubio A.Pollacco D.Pozuelos F.J.Queloz D.Ragazzoni R.,Rando N.Rauer H.Ribas I.Santos N.C.Scandariato G.Smith A.M.S.,Sousa S.G.Steller M.Szabo Gy.M.Segransan D.Thomas N.Udry S.,Ulmer B.Van Grootel V.Walton N.A.2021-12-03T12:53:36Z2021-09-30T09:22:47ZCDS support team

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

cds-question@unistra.frmultiple-starsexoplanetsphotometry55 Cnc e is a transiting super-Earth (radius 1.88R_{Earth}_ and mass 8M_{Earth}_) orbiting a G8V host star on a 17-hour orbit. Spitzer observations of the planet's phase curve at 4.5um revealed a time-varying occultation depth, and MOST optical observations are consistent with a time-varying phase curve amplitude and phase offset of maximum light. Both broadband and high-resolution spectroscopic analyses are consistent with either a high mean molecular weight atmosphere or no atmosphere for planet e. A long term photometric monitoring campaign on an independent optical telescope is needed to probe the variability in this system. We seek to measure the phase variations of 55 Cnc e with a broadband optical filter with the 30 cm effective aperture space telescope CHEOPS and explore how the precision photometry narrows down the range of possible scenarios. We observed 55 Cnc for 1.6 orbital phases in March of 2020. We designed a phase curve detrending toolkit for CHEOPS photometry which allows us to study the underlying flux variations of the 55 Cnc system. We detected a phase variation with a full-amplitude of 72+/-7ppm but do not detect a significant secondary eclipse of the planet. The shape of the phase variation resembles that of a piecewise-Lambertian, however the non-detection of the planetary secondary eclipse, and the large amplitude of the variations exclude reflection from the planetary surface as a possible origin of the observed phase variations. They are also likely incompatible with magnetospheric interactions between the star and planet but may imply that circumplanetary or circumstellar material modulate the flux of the system. Further precision photometry of 55 Cnc from CHEOPS will measure variations in the phase curve amplitude and shape over time this year.2021A&A...653A.173Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/653/A173CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/533/A114 : Transit of super-Earth 55 Cnc e (Demory+, 2011)J/A+A/539/A28 : super-Earth 55 Cnc e new transit photometry (Gillon+, 2012)J/A+A/545/A97 : 0.8-6{mu}m calibrated spectrum of 55 Cnc (Crossfield, 2012)J/ApJ/778/132 : C and O abundances in 55 Cnc (Teske+, 2013)J/ApJ/792/L31 : HARPS and HARPS-N 55 Cnc radial velocitiesJ/A+A/619/A1 : 55 Cnc radial velocities and photometry (Bourrier+, 2018)J/A+A/615/A117 : 55 CnC geocoronal emission lines template (Bourrier+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/653/A173https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/653/A173http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/653/A173https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/653/A173https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/653/A173http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/653/A173GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/653/A173/photomPhotometric dataFluxNormalized fluxphot.flux;arith.ratiodoublerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBJDBarycentric Julian Date (TDB)dtime.epochdoublee_FluxNormalized flux errorstat.error;phot.fluxdoubleRollAngleSpacecraft roll angledeginstr.offsetdoubleContamAperture flux contaminationinstr.backgrounddoubleFluxDetrendDetrended normalized fluxphot.flux;arith.ratiodouble