Multi-wavelength light curves from CTA 102. The entire period is from 2012 September 30 to 2018 October 9 (MJD 56200–58400). From top to bottom, the panels show light curves in γ-rays, X-rays, optical, and radio with different colours and symbols indicating different frequencies. The red triangles in the γ-ray light curve indicate upper limits on the flux density. The optical and radio light curves are displayed with arbitrary offsets for clarity. The grey horizontal lines for the γ-ray light curve denote the flux density threshold (see the text for details). The black dotted lines indicate the peaks of the γ-ray flares (1–6). The grey shaded areas mark three periods (P1–3) for the cross-correlation analysis.