The European Space Agency's Gaia mission is revolutionising our understanding on how the Milky Way, the spiral galaxy we inhabit, has formed and evolved. Gaia is measuring the apparent luminosities, colours, positions, motions, and the chemical composition of an unprecedentedly large number of individual stars in our Galaxy. In particular, combining apparent luminosities with distances to these stars, here we have computed the intrinsic luminosity of 24 million stars within a sphere of 6500 light years around our Sun. Comparing such luminosities and colours with accurate models of stars we

The main emission mechanisms of the interstellar medium (ISM) in the spectral range between the radio and the far infrared are very well characterised and understood, both observationally and theoretically, for decades. However, in the late 90s a new mechanism was discovered in the microwaves, that has been coined “anomalous microwave emission” (AME). A basic feature of this emission is its tight spatial correlation with the thermal emission from ISM dust grains. This means that the AME observed intensity is stronger in regions with a higher abundance of ISM grains. This led to the proposal