Cepheids are important stars for the well-known relation between the period of their pulsations and their intrinsic luminosities. These stars are in fact characterized by regular pulsations whose period increases linearly with their absolute magnitude. Cepheids have a mass of about 5 solar masses, thus their progenitors are B stars in Main Sequence. However, their evolutionary path can be affected
The study of binary systems plays an important role in several fields of astronomy such as stellar evolution and galactic archeology since it allows direct measurements of stellar parameters such as masses, radii, and luminosities. Multiple stellar systems have typically small angular separation and thus they are not resolved by direct imaging. In these cases spectroscopy is a powerful tool
