From top to bottom: the XRT, UVOT, AAVSO data and X-ray hardness ratio (0.45–1/0.3–0.45 keV) each folded on the 1.77 d ephemeris given in the text. All three light-curve datasets are in phase with each other and cover the same time interval of  ~days 71–84 (defined by the availability of AAVSO unfiltered data). The Swift XRT and UVOT datasets have been averaged into 20 and 40 phase bins per cycle respectively, with the uncertainties being the standard errors on the mean. The X-ray hardness ratio shows no significant variation during the 1.77 d interval.