Empirical models of stellar flares: constraints on flare theories

A review is presented on empirical flare models of UV Cet type stars based upon optical, UV, X-ray, and radio observations. The observational constraints on the flare energetics, nature of radiation sources, and flare structures are discussed, with special attention to the geometrical dimension and the magnetic field of the flaring region. The hot-plasma model in the solar analogy is critically examined by comparing it with observations. Possible future observations are suggested to tighten the constraints on the stellar flare theories. (Auth.)