My current research focuses on establishing observational constraints on the origins of the chemical elements in the Galaxy and the Universe through spectroscopic analysis of low-metallicity stars. Below you can find an interactive plot with a few selected synthetic spectra for stars with different metallicities ([Fe/H] - upper panel) and different carbon abundances ([C/Fe] - lower panel). All the spectra have the same effective temperature (Teff = 5250K) and surface gravity (logg=2.5).