2008PASP..120..311P

We have obtained differential uvby and UBV photometry of the B8Iae variable HD 199478 (HR 8020) over 2500 days, in order to study the photometric variability of this star, and to compare it with various aspects of the spectroscopic variability. The total peak-to-peak amplitude was about 0.15 mag in each filter. Color variability was present, but complex. The photometric data were analyzed using self-correlation and Fourier analysis; the latter was hampered by the complexity of the variability, and by the presence of two annual seasonal gaps in the data. Although the variability was not strictly periodic, there are characteristic time scales of 20 days, and occasionally 50 days, in many seasons. These are consistent with the time scales of spectroscopic variability. There was no obvious photometric counterpart to the unusual spectroscopic behavior in 2000 October. We discuss the results in the context of recent theoretical studies of hot supergiant variability.