#diffraction grating
- Astrospectroscopy — An elite branch of practical astrophysics dealing with the photography, digital recording, and structural analysis of the electromagnetic radiation spectra emitted or absorbed by celestial bodies. By decomposing stellar light using prisms or diffraction gratings attached to telescopes, astrospectroscopy enables the determination of chemical composition, temperature, pressure, radial velocity, and magnetic field strength of objects in the universe.