How scientists use spectra to determine the composition of stars?

Scientists analyze the spectra of stars by observing the light they emit or absorb, which reveals specific patterns of wavelengths. Each element has a unique spectral signature, consisting of distinct absorption or emission lines. By comparing these lines to known wavelengths, scientists can identify the chemical composition, temperature, density, and movement of the star. This technique, known as spectroscopy, allows astronomers to gain insights into the star's lifecycle and the processes occurring within it.