* Light from the star is collected: Telescopes gather light from distant stars.
* Light is split into its component colors: The spectrograph separates the light into its different wavelengths, creating a spectrum.
* Analyzing the spectrum: Each element in the star absorbs specific wavelengths of light, leaving dark lines in the spectrum (called absorption lines). The pattern of these lines is unique to each element.
* Identifying the elements: By comparing the absorption lines to known patterns of elements, astronomers can determine the chemical composition of the star.
So, while telescopes are used to collect the light, it's the spectrograph that allows astronomers to analyze the light and decipher the star's chemical makeup.
