The first large-scale age-map of the Milky Way..........

The Milky Way is a spiral galaxy with a bulge at the centre, thousands of light years in diameter, that contains about a quarter of the total mass of stars. Previous studies have shown that the bulge hosts two components: a population of metal-poor stars that have a spherical distribution, and a population of metal-rich stars that form an elongated bar with a "waist," like an x or a bi-lobed peanut. However, analyses of the ages of the stars to date have produced conflicting results.