Massive stars in low metallicity environments

Nonetheless, it is still widely uncertain due to a deficit of observational evidence to verify theoretical models. Recent surveys of the galaxy and Magellanic clouds in addition to continuous development of stellar evolution codes are, however, replenishing the domain of massive stars so that we may probe the characteristics of their evolution to better understand the early stages of their life. <br><br>The evolution of massive stars is highly heterogeneous, sensitive to mass loss, internal mixing, metallicity, rotation, binarity, and magnetic fields.

In this thesis, I have probed the evolution of massive stars for a range of metallicities, including our Milky Way galaxy and the Magellanic Clouds. This work provides an insight into the evolutionary models conducted in an endeavour to understand the dominant physical processes acting on massive stars, chapters 3 and 4. Theoretical predictions of the upper luminosity limit of red supergiants and constraints on internal mixing processes such as convective overshooting and semiconvection are presented in chapter 5.