The composition of a star can be accurately determined using spectroscopy.

Spectroscopy is the scientific study of how matter interacts with electromagnetic radiation. By analyzing the spectrum of light emitted by a star, astronomers can uncover its chemical composition. Each element in the star absorbs and emits light at specific wavelengths, resulting in a distinctive spectral signature.

To capture a star’s spectrum, astronomers utilize a spectrograph, which separates the incoming light into its constituent colors. The resulting spectrum is then examined to identify absorption and emission lines, which are linked to specific elements. By comparing the observed spectrum with known spectra of various elements, astronomers can ascertain the relative abundance of each element present in the star.

In addition to revealing a star’s chemical composition, spectroscopy also provides insights into its temperature, density, and velocity. By measuring the Doppler shift of spectral lines, astronomers can determine whether a star is moving toward or away from Earth, as well as the speed of that movement.

Overall, spectroscopy serves as a powerful tool for gaining a deeper understanding of the properties of stars and other celestial bodies. By analyzing the light they emit, astronomers can uncover details about their composition, structure, and evolution, thus enhancing our comprehension of the universe.