spectrograph An instrument that disperses (breaks apart) light into a spectrum so that the intensity at different wavelengths can be measured by a detector. It consists of a slit for isolating the light from a particular object in the telescopes field of view, a collimator for directing this light into a parallel beam, a diffraction grating or prism for creating the spectrum, and a detector for recording the spectrum. In the past the detector would have been a photographic plate but today CCDs, which are far more sensitive, are typically used instead. Related category • SPECTRA AND SPECTROSCOPY Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) |