Top: lightcurve of HD 163296 in V (0.55 μm) and L (3.76 μm). The dotted line and the gray shaded areas correspond to the mean value and 1σ spread. The time intervals denoted above the V-band lightcurve are expanded in the bottom panel. Horizontal bars indicate the jet launch epochs estimated from radial velocities (Sect. 3.1). Bottom: V-band lightcurve for selected intervals, exhibiting the shape, duration, and frequency of the fading events. The calendar date corresponding to the minimum value on the x-axis is displayed in the bottom left corner of each graph. References for plot symbols: (1) de Winter et al. (2001); (2) Manfroid et al. (1991); (3) Maidanak Observatory (Grankin et al., in prep.); (4) Swiss (this work); (5) Perryman et al. (1997); (6) Hillenbrand et al. (1992); (7) Eiroa et al. (2001); (8) Pojmanski & Maciejewski (2004); (9) AAVSO (this work); (10) Tannirkulam et al. (2008b); (11) Mendigutía et al. (2013); (12) Sitko et al. (2008); (13) de Winter et al. (2001); (14) Berrilli et al. (1992); (15) BASS; (16) SpeX (Sitko et al. 2008, this work). See Table A.1 for more details.