The birth of the Milky Way as uncovered by accurate stellar ages with Gaia

Understand

Knowledge of ages for stars formed over a galaxy's lifetime is fundamental to understand its formation and evolution.

• However, stellar ages are difficult to obtain since they cannot be measured from observations, being comparison with stellar models (Soderblom 2010) required.
• Alternatively, age distributions can be derived applying the robust technique of colour-magnitude diagram fitting (Gallart et al.
• 2005), till now mainly employed to study nearby galaxies.