[en] A thermal model of a cometary nucleus is analyzed on the basis of a numerical solution of the nonsteady heat-conduction equation with allowance for energy balance at the surface, variability of the thermophysical characteristics of the material, the influence of the dust component, and the proper rotation and orbital motion of the comet. The temperature fields are calculated and the reactive force generated in the anisotropic outflow of volatile components of the nucleus is estimated. Using the characteristics of the thermal model, a photometric model of the region near the nucleus is constructed, containing quantitative estimates of the optical properties of the nucleus and the gas - dust atmosphere. The problem of the brightness distribution in the vicinity of a cometary nucleus is investigated qualitatively