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Paper: Long-term VRI photometry of P Cygni
Volume: 233, P Cygni 2000: 400 Years of Progress
Page: 31
Authors: Percy, J. R.; Evans, T. D. K.; Henry, G. W.; Mattei, J. A.
Abstract: We report over 13 years of photometric observations of P Cygni from a robotic telescope (VRI: JD 2446512-2451360), from the American Association of Variable Star Observers (AAVSO) photoelectric photometry program (V: JD 2446200-2451500), and from the AAVSO visual program (mv: JD 2443500-2451500 and some earlier observations). We have analyzed these observations using light curves, Fourier analysis, and autocorrelation analysis. Light curves of the two photoelectric datasets show variations of up to 0.1 magnitude on time scales of years, months, weeks, and as short as 10 days. Fourier analysis and autocorrelation analysis show that the variations are not periodic, but there are characteristic time scales of 50-200 days and also around 400 days. The visual data, when corrected for a small (0.01) seasonal effect, are capable of revealing variations of 0.1 magnitude on time scales of years, but the evidence for longer-term (decades) variations is weak. The time scales and amplitudes which we have observed are in accord with previous results. Our data provide a useful comparison with data obtained spectroscopically, or at other wavelenghts.
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