J/A+AS/114/79ivo://CDS.VizieR/J/A+AS/114/79CDSLeroy J.L.2000-03-29T05:30:25Z2000-03-29T05:30:19ZCDS support team

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

cds-question@unistra.frap-starspolarimetryA systematic program of broadband linear polarimetry, bearing on 55 Ap stars, has been developed during the 4 last years, at the Pic du Midi Observatory. While separate data have been already published, we present in this paper a complete catalogue of our observational material, including more than 400 measurements. We complement these data with another 100 measurements, obtained previously by other authors, so as to get a synthetic view of the phenomenon. Most of the observations have been dedicated to a small number (15) of stars, which show conspicuous changes of the linear polarization, so that it is possible to know accurately the time variation of the Stokes parameters: we expect that these new data will really improve our knowledge of the magnetic configuration, after a proper analysis which is currently being developed. For the other 40 stars, the polarization is either too small, or strongly contaminated by the interstellar polarization, so that broadband polarimetry is not very effective. Anyway, this first systematic investigation on the linear polarization of Ap stars will be a useful starting point for future measurements which should be made with higher spectral resolution. Finally, our measurements have provided new determinations of the rotation period for several stars.1995A&AS..114...79Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+AS/114/79CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+AS/114/79https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+AS/114/79http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+AS/114/79https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+AS/114/79https://vizier.iucaa.in/viz-bin/votable?-source=J/A+AS/114/79http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+AS/114/79GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/A+AS/114/79/polarizPolarization data (polariz.dat 1 to 68)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarStar name (1)meta.id;meta.maincharprimarySimbadask the SIMBAD data-base about this objectcharFilterFilter (2)meta.code;instr.filtercharJDJulian Datedtime.epochdoublePolPolarization degree%phys.polarizationfloatThetaPolarization orientationdegpos.posAng;phys.polarizationintQ/IReduced Stokes parameter Q/I%phys.polarization.stokesfloatU/IReduced Stokes parameter U/I%phys.polarization.stokesfloate_Q/IStandard deviation on Q/I and U/I%stat.errorfloatJ/A+AS/114/79/table69Fourier coefficients of the Q/I and U/I expansionrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarStar namemeta.id;meta.maincharprimaryZQFourier coefficient Z_Q_stat.fit.paramfloatAQFourier coefficient A_Q_stat.fit.paramfloatBQFourier coefficient B_Q_stat.fit.paramfloatCQFourier coefficient C_Q_stat.fit.paramfloatDQFourier coefficient D_Q_stat.fit.paramfloatEQ[]? Fourier coefficient E_Q_stat.fit.paramfloatnullableFQ[]? Fourier coefficient F_Q_stat.fit.paramfloatnullableGQ[]? Fourier coefficient G_Q_stat.fit.paramfloatnullableHQ[]? Fourier coefficient H_Q_stat.fit.paramfloatnullableIQ[]? Fourier coefficient I_Q_stat.fit.paramfloatnullableJQ[]? Fourier coefficient J_Q_stat.fit.paramfloatnullableZUFourier coefficient Z_U_stat.fit.paramfloatAUFourier coefficient A_U_stat.fit.paramfloatBUFourier coefficient B_U_stat.fit.paramfloatCUFourier coefficient C_U_stat.fit.paramfloatDUFourier coefficient D_U_stat.fit.paramfloatEU[]? Fourier coefficient E_U_stat.fit.paramfloatnullableFU[]? Fourier coefficient F_U_stat.fit.paramfloatnullableGU[]? Fourier coefficient G_U_stat.fit.paramfloatnullableHU[]? Fourier coefficient H_U_stat.fit.paramfloatnullableIU[]? Fourier coefficient I_U_stat.fit.paramfloatnullableJU[]? Fourier coefficient J_U_stat.fit.paramfloatnullableChi2/nuRatio of Chi-squared to the number of degrees of freedomstat.fit.paramfloat