 Faint Object Spectrograph

The Faint Object Spectrograph (FOS) is an instrument that was used on the Hubble Space Telescope (HST) to analyze the light from faint astronomical objects, enabling astronomers to study their composition, temperature, motion, and other physical properties. The FOS was particularly effective for spectroscopic measurements, which involve breaking down light into its constituent wavelengths to identify the chemical elements present in celestial bodies.