J/A+AS/114/79 J/A+AS/114/79 Polarimetry of Ap stars: general catalogue J L Leroy Astron. Astrophys. Suppl. Ser. 114 79 1995 1995A&AS..114...79L catalogs polarization stars: chemically peculiar stars: magnetic fields A 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.

Star Star name number=1 HD 11502 = {gamma} Ari S HD 11503 = {gamma} Ari N --- Filter Filter number=2 B : B filter Ba : B filter; Piirola and Tuominen 1981 Bb : B filter; Breger et al. 1989 Bc : B filter; Berdyugin et al. 1992 exB : extended-B filter; Kemp and Wolstencroft 1974 L : {lambda}=4200A filter L5 : {lambda}=5200A filter LB : {lambda}=4200A or B filter --- JD Julian Date d Pol Polarization degree % Theta Polarization orientation deg Q/I Reduced Stokes parameter Q/I % U/I Reduced Stokes parameter U/I % e_Q/I Standard deviation on Q/I and U/I % Star Star name --- ZQ Fourier coefficient Z_Q_ --- AQ Fourier coefficient A_Q_ --- BQ Fourier coefficient B_Q_ --- CQ Fourier coefficient C_Q_ --- DQ Fourier coefficient D_Q_ --- EQ Fourier coefficient E_Q_ --- FQ Fourier coefficient F_Q_ --- GQ Fourier coefficient G_Q_ --- HQ Fourier coefficient H_Q_ --- IQ Fourier coefficient I_Q_ --- JQ Fourier coefficient J_Q_ --- ZU Fourier coefficient Z_U_ --- AU Fourier coefficient A_U_ --- BU Fourier coefficient B_U_ --- CU Fourier coefficient C_U_ --- DU Fourier coefficient D_U_ --- EU Fourier coefficient E_U_ --- FU Fourier coefficient F_U_ --- GU Fourier coefficient G_U_ --- HU Fourier coefficient H_U_ --- IU Fourier coefficient I_U_ --- JU Fourier coefficient J_U_ --- Chi2/nu Ratio of Chi-squared to the number of degrees of freedom --- Simona Mei CDS 1995Jul05 J_A+AS_114_79.xml