# The Early Generations of Rotating Massive Stars and the Origin of Carbon-Enhanced Metal-Poor Stars

## TL;DR

This paper investigates the role of early rotating massive stars in the universe's chemical evolution by modeling their evolution and nucleosynthesis, and comparing results with observations of ancient, metal-poor stars.

## Contribution

It combines stellar evolution models with nucleosynthesis and observational data to explore the origins of CEMP stars and the physics of early massive stars.

## Key findings

- Rotating massive star models can reproduce observed CEMP star abundances.
- Rotation significantly influences nucleosynthesis yields in early massive stars.
- The results support a link between early massive stars and the formation of CEMP stars.

## Abstract

The study of the long-dead early generations of massive stars is crucial in order to obtain a complete picture of the chemical evolution of the Universe, hence the origin of the elements. The nature of these stars can be inferred indirectly by investigating the origin of low-mass metal-poor stars observed in our Galaxy, some of which are almost as old as the Universe. The peculiar extremely iron-poor Carbon-Enhanced Metal-Poor (CEMP) stars, whose precise origin is still debated, are thought to have formed with the material ejected by only one or very few previous massive stars. The main aim of this thesis is to explore the physics and the nucleosynthesis of the early generations of massive stars. It is achieved by combining stellar evolution modeling including rotation and full nucleosynthesis with observations of CEMP stars.