A Theoretical Study of the Stellar Parameters and Surface Nucleosynthesis of the Extremely Metal-Poor RGB Giant BD$-18^{\circ }$5550 - Part I: Effects of $\alpha$-enhancement and Internal Mixing

Mrinmay Medhi, Upakul Mahanta, Swapnajyoti Sarma +1

We present a detailed stellar evolution study of BD$-18^{\circ }$5550, an extremely metal-poor red giant star in the Galactic halo. Such stars are among the oldest known objects and…