What kind of stars are present in the halo of the Milkyway? Explain why.?

Answer 1

The halo is the spherical distribution of stars around the galaxy. It is composed of old stars (population II) formed early in the history of the galaxy. Because of their age, the metallicity of these stars is low.All the hot massive stars have long since gone supernova, leaving smaller, redder stars. There is no new star formation going on in the halo, because all its gas clouds have dissipated. In the disc, on the other hand, gas and dust get compressed by the density waves in the spiral arms, leading to ongoing star formation.