New UBV light curves and some infrared JHK observations of the RS CVn-type binary SV Camelopardalis are presented. New determinations of primary minimum epochs confirm the presence of a light-time effect, with a period U = 74.7 yr. The overall shape of the light curve appears to vary in time by several hundredths of magnitude, due to a distortion wave whose fast migration causes an inversion in the levels of the maxima in a few months. IR excesses strongly suggest the presence of cool regions, in agreement with the common hypothesis that the light variations are due to starspots. By the method of Vogt (1981) spot temperatures turn out to be near 3800 K, about 1500 K cooler than the quiet photosphere. The spot hypothesis is also consistent with the changes in luminosity observed in the interval 1969-1984, which are shown to be tightly correlated with the cycles of stellar activity, as derived by the model of Busso et al. (1984).
The RS CVn-type binary SV Camelopardalis - Evidence of dark spots from UBV observations and IR fluxes
BUSSO, Maurizio Maria
1985
Abstract
New UBV light curves and some infrared JHK observations of the RS CVn-type binary SV Camelopardalis are presented. New determinations of primary minimum epochs confirm the presence of a light-time effect, with a period U = 74.7 yr. The overall shape of the light curve appears to vary in time by several hundredths of magnitude, due to a distortion wave whose fast migration causes an inversion in the levels of the maxima in a few months. IR excesses strongly suggest the presence of cool regions, in agreement with the common hypothesis that the light variations are due to starspots. By the method of Vogt (1981) spot temperatures turn out to be near 3800 K, about 1500 K cooler than the quiet photosphere. The spot hypothesis is also consistent with the changes in luminosity observed in the interval 1969-1984, which are shown to be tightly correlated with the cycles of stellar activity, as derived by the model of Busso et al. (1984).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
