Fermi-gst: A new view of the gamma-ray sky

The Large Area Telescope on the Fermi gamma-ray Space Telescope (FGST, ex-GLAST) provides unprecedented sensitivity for all-sky monitoring of gamma-ray activity. It is an adequate telescope to detect transient sources, since the observatory scans the entire sky every three hours and allows a general search for flaring activity on daily timescale. This search is conducted automatically as part of the ground processing of the data and allows a fast response -less than a day- to transient events. Follow-up observations in X-rays, optical, and radio are then performed to attempt to identify the origin of the emission and probe the possible existence of new transient gamma-ray sources in the Galaxy. Since its launch on 11th June 2008, Fermi-LAT has detected nearly 1500 gamma-ray sources, nearly half of them being extragalactic. After a brief census of detected celestial objects, we report here on the LAT results focusing on Galactic transient binary systems. The Fermi-LAT has detected 2 gamma-ray binaries, a microquasar and an unexpected new type of gamma-ray source: a symbiotic nova.