From top to bottom: optical, ultraviolet, soft, and hard X-ray light curves obtained in 2005 (left) and 2015 (right). They were obtained from the AAVSO data base, with the optical monitor and with EPIC onboard XMM-Newton, and with NuSTAR, respectively. Original photon data were binned with a time bin size of 30 s. Phase-averaged light curves have 40 bins per orbital cycle. All data are shown twice for better visibility. The OM-filters were not the same in 2005 and 2015. The y-axis scale for 2015 have been compressed by a factor of 3. The soft X-ray light curves (third panel from above) were built using photons in the energy range 0.2−0.5 keV with EPIC-MOS (2005) and EPIC-pn (2015) with the thin and the thick filters, respectively (see Table 1). The hard X-ray light curves are based on EPIC-pn (2005) covering the energy range 2−10 keV and NuSTAR (2015, no energy selection). Colors of individual data points obtained in 2005 indicate different satellite orbits (2005 data, color – orbit): green – 1027, red – 1028, cyan – 1029, blue – 1030, magenta – 1031.