Astrophysics (index)about


(instrument measuring brightness)

A Photometer is an instrument measuring brightness, used in observing stars, etc., i.e., determining their Magnitude.

A CCD is essentially a grid of photometers, and a photometer in modern astronomy may be a CCD, aiming to catch all the Photons from a star. The apparent brightness of a star is found by adding the count of all the photons received in the Airy Disk of the star in question.

(EMR,visible light,instrument type)

Referenced by:
Hubble Space Telescope (HST)
Mercator Telescope
Spitzer Space Telescope (SST)
2dF Galaxy Redshift Survey (2dFGRS)