STREGA: STRucture and Evolution of the GAlaxy with the VST

Marconi, M.; Musella, I.; Di Criscienzo, M.; Cignoni, Michele; Dall'Ora, M.; Bono, G.; Ripepi, V.; Brocato, E.; Raimondo, G.; Grado, A.; Limatola, L.; Coppola, G.; Moretti, M. I.; Stetson, P. B.; Calamida, A.; Cantiello, M.; Capaccioli, M.; Cappellaro, E.; Cioni, M. R. L.; Degl'Innocenti, Scilla; De Martino, D.; Di Cecco, A.; Ferraro, I.; Iannicola, G.; PRADA MORONI, PIER GIORGIO; Silvotti, R.; Buonanno, R.; Getman, F.; Napolitano, N. R.; Pulone, L.; Schipani, P.

STREGA (STRucture and Evolution of the Galaxy) is an ongoing VLT Survey Telescope Guaranteed Time survey, covering an area of about 150 square degrees, aimed at investigating the mechanisms of formation and evolution of the Galactic Halo. The project is organised into two parts: a core programme to search for the signatures of interaction between selected stellar systems and the Galactic Halo and a complementary part focussed on the southern portion of the Fornax Stream. The basis is the use of variable stars (RR Lyrae and long period variables) and main sequence turn-off stars as tracers of stellar overdensities. Observations in g,r,i bands, with additional filters, u, Strömgren v and Hα for selected fields, will allow investigation of the properties of Halo white dwarfs and interacting binaries. We present an overview of the survey and some first results, in particular for the region centred on Omega Centauri.