High-speed multicolor photometry of an Ursae Majoris

Abstract

view Abstract Citations (19) References (29) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS High-Speed Multicolor Photometry of an Ursae Majoris Imamura, James N. ; Steiman-Cameron, Thomas Y. Abstract Results are reported of multibandpass optical photometry of the AM Her object, AN UMa Fourier techniques were used to search for variability on time scales ranging from milliseconds to tens of seconds. Longer term behavior was studied using photometric light curves. Middleditch (1982) found that the power spectrum of AN UMa, if averaged over times longer than about 10 minutes, showed 'excess' power over the frequency range 0.4-1 Hz, but he did not study the behavior for individual time intervals shorter than 10 minutes. The broad feature can be resolved into multiple features of width 0.02 Hz or less when power spectra are calculated for time intervals of about 1 minute. This suggests that the noisar feature at a given time is the superposition of many discrete periodicities of limited coherence. The light curves show two distinct minima at polarization phases 0.1 and 0.55, with the possibility of a third minimum near 0.3. The results are consistent with earlier results if there are two or more optical emission regions fixed in the frame of the binary system whose luminosities vary as a function of time. Publication: The Astrophysical Journal Pub Date: December 1986 DOI: 10.1086/164816 Bibcode: 1986ApJ...311..786I Keywords: Magnetic Stars; Stellar Spectrophotometry; Visible Spectrum; White Dwarf Stars; X Ray Binaries; Fourier Analysis; Light Curve; Polarization Characteristics; Power Spectra; Stellar Mass Accretion; Stellar Oscillations; Astrophysics full text sources ADS | data products SIMBAD (2)