  One of the ways to understand the genesis and evolution of the universe is to
know how galaxies have formed and evolved. In this regard, the study of star
formation history (SFH) plays an important role in the accurate understanding
of galaxies. In this paper, we used long-period variable stars (LPVs) to
estimate the SFH in the Andromeda galaxy (M31). These cool stars reach their
peak luminosity in the final stage of their evolution; their birth mass is
directly related to their luminosity. Therefore, we construct the mass function
and the star formation history using stellar evolution models.
