Combined light curve from 1890 to 2018. The light curves from seven sources have been overplotted with vertical offsets so as to display the century-long ups and downs of KIC 8462852. In particular, care has been made to determine and display the relative vertical positioning of the 1890–1991 and 2006–2018 segments. This is critical in showing that the ‘baseline’ in recent years is 0.124 mag fainter than the brightness in the 1890s, thus showing that the modern IR observations were taken at a time when dust covered at least 12.4 per cent of the starlight. The issue is that this near-periastron dust must have emitted a significantly detectable amount of IR light, with such not being seen by many observers. Our B-band light curve is the blue line, seen tightly compressed in the middle of the far right-hand side. The Harvard B-band light curve is the black line from the upper left to the lower right, and this is correctly placed vertically to be calibrated with the light curve from this paper. The Maria Mitchell light curve from archival plates is the decadal weighted average, vertically shifted to most closely match the Harvard archival data. The Kepler light curve is shown as a grey curve in the middle of the right-hand side, with the deep dips extending below the bottom of the plot. The Las Cumbres r’-band light curve is red dots, shifted vertically to match our light curve, and it covers well the blue line from the light curve from this paper. The ASAS-SN V-band light curve is represented by a light-green line that closely overlaps our blue curve in the far right of the graph. The ASAS light curve (dark-green dots) has been combined to 10-d bins and then vertically shifted to optimally match our light curve, with this tying the cross-calibration back to the Kepler light curve.