On the occasion of the summer solstice, the Tunis Science City organized, in collaboration with the astronomical society of Tunisia, a day entirely dedicated to the Sun. A rich and varied programmed was elaborated including solar observations, workshops, as well as a lecture entitled “The Sun, its origins and its structure” , which was given by Pr. Nejim-Edine Jaidane, professor of physics at the faculty of sciences of Tunis.