Comunicazione
Classical Cepheids as population tracers in the Milky Way and in the Magellanic Clouds.
Ripepi V.
Classical Cepheids (DCEPs) variables are important tracers of the young ($t\sim$ 50--300 Myrs) populations in the Milky Way and other galaxies of the Local Group, such as the Magellanic Clouds. In this talk, I present some recent results based on Data Release 3 of the Gaia mission and ground-based photometry concerning the use of DCEPs to trace the Galactic disc and spiral arms and the tridimensional structure of the Magellanic Clouds.