Young stars discovered in dwarf spheroidal galaxies confirm their recent infall into the Milky way

Francois Hammer, Piercarlo Bonifacio, Elisabetta Caffau +10

Recent observations from the ESA Gaia satellite and with the ESO VLT, have identified the presence of a population of young, 0.5 to 2 Gyr old, stars in the halo and in dwarf sphero…