In astronomy, photometers are used to measure the brightness of stars or of other celestial objects. A photoelectric photometer records the electric current generated when light from a source falls onto a light-sensitive surface, kicking off electrons, which are then amplified into a measurable current by a photomultiplier. An area photometer, or imaging photometer, on the other hand, measures simultaneously the light intensity at each point of an extended object such as a nebula or galaxy using CCD detectors or an infrared array.
Related entry photometry
Related categories INSTRUMENTATION
OPTICS AND OPTICAL PHENOMENA
Home • About • Copyright © The Worlds of David Darling • Encyclopedia of Alternative Energy • Contact