Top: I-band light curve of AzV 261 spanning from 1998 to 2009. Also shown is the scaled historical light curve of the classic LBV star S Doradus for comparison (crosses). Panel b: (V−I) colour plotted against the Julian date for AzV 261. Middle: (panel a) light curve with the overall trend removed by a fourth-degree polynomial, with the best-fit predicted light curve (the three peaks are given in Table 1). Panel b: residuals between the fit period and the observed light curve. Bottom: V vs. (V−I) colour-magnitude diagram of AzV 261 over time, with time given by the colourbar. The behaviour of a brightness increase corresponding to a temperature decrease is seen here.