The variable linear polarization of Cygnus X-1, 1974-1975 observations

Abstract

view Abstract Citations (17) References (8) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The variable linear polarization of Cygnus X-1, 1974 - 1975 observations. Kemp, J. C. ; Southwick, R. G. ; Rudy, R. J. Abstract An interim report is given concerning a long-range UBV observational study of linear polarization variations in HDE 226868, the optical counterpart of Cyg X-1. The observed rms fluctuations per night for either of the Stokes parameters are found to be approximately 0.33% for the U filter and 0.28% for either the B or the V filter, indicating that real variability is present with overwhelming probability. Very accurate measures of the average polarization are made for each filter. A folding of the data from each color on the period of 5.600 days reveals no significant phase locking and no statistically significant Fourier components at either the fundamental or half period. Power spectra of the variations are shown to be very noisy in appearance and to exhibit marginal evidence for anisotropic concentrations of excess power around the fundamental and half periods. The suspected structure in the power spectra, which does not consist of simple peaks, is explained tentatively in terms of phase modulation of an otherwise phase-locked process. Correlation with variable circular polarization is briefly examined. Publication: The Astrophysical Journal Pub Date: November 1976 DOI: 10.1086/154823 Bibcode: 1976ApJ...210..239K Keywords: Optical Polarization; Power Spectra; Supergiant Stars; Ubv Spectra; X Ray Sources; Black Holes (Astronomy); Circular Polarization; Optical Filters; Tables (Data); Astrophysics full text sources ADS | data products SIMBAD (1)