Spectral Analysis of Starlight (IMAGE) Max-Planck-Gesellschaft Caption An optical fiber is used to guide the light collected in telescopes to the spectrograph, where it is split up into its individual colors. These are then compared with the frequency comb -- seen here as equally spaced lines -- to obtain an accurate determination of the color. Credit ESO Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.