The optical, UV, and X-ray light curves around the time of ignition. Fluxes and magnitudes are corrected for Galactic absorption. Top: The X-ray light curve, consisting of the eROSITA, XMM-Newton, Swift-XRT, and NICER data. Bottom: Light curves for ATLAS c and o, Gaia g, Swift-UVOT, and PROMPT6 R data. These data are not host subtracted. The data are plotted in time relative to the point of the first peak in the o-band light curve (see Section 3.1.6). The dashed vertical lines represent the epochs for our optical spectroscopy. The optical data show a sharp increase over approximately 3 weeks, followed by a sharp turnover, a further bump visible in the o and c bands, and subsequent decline. The decline in optical brightness is matched in the UV and X-ray data.