Variations in the variability of RR Tel.

Abstract

The visible-light periodicity of the very slow nova RR Tel is inferred to vary in cycles of 350- to 410-day periods, based on the uvby photometric data, IUE FES measurements, and AAVSO visual estimates. Besides a general increase in magnitude, the visible lightcurve is also marked by two events corresponding to sudden decreases of brightness in 1949 and 1962/1963. A comparison with infrared data does not rule out the possibility of a phase shift of 10 days at most between both sets of data for a common time coverage. It is noted that additional spectroscopic and photometric observations are necessary to link the Mira components to the variations in the visible range.