A device, a system, and a method for simulating sunlight by reducing operating costs and maintaining relatively high accuracy through the use of a low-cost light source and a modified light source power supply conversion table. The illuminating device includes: at least one incandescent light source at a temperature not exceeding 5000K; at least one station, which receives light from the at least one the incandescent light source and has a support to support a small body to be illuminated; an electronic control unit, for variable powering of the incandescent light source and including at least one electronic processing device (a microprocessor and a memory device connected in data exchange with the microprocessor); and a control unit programmed for receiving construction data of the small body and the atmosphere, storing the reference table for power supply conversion, and powering the incandescent light source based on the reference table.