A White-light Flare Powered by Magnetic Reconnection in the Lower Solar Atmosphere

White-light flares (WLFs), first observed in 1859, refer to a type of solar flare showing an obvious enhancement of the visible continuum emission. This type of enhancement often occurs in most energetic flares, and is usually interpreted as a consequence of efficient heating in the lower solar atmosphere through nonthermal electrons propagating downward from the energy release site in the corona. However, this coronal-reconnection model has difficulty in explaining the recently discovered small WLFs. Here we report a C2.3 WLF, which is associated with several observational phenomena: a fast decrease in opposite-polarity photospheric magnetic fluxes, the disappearance of two adjacent pores, significant heating of the lower chromosphere, a negligible increase of the hard X-ray flux, and an associated U-shaped magnetic field configuration. All these suggest that this WLF is powered by magnetic reconnection in the lower part of the solar atmosphere rather than by reconnection higher up in the corona.