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 a grid of tiny photometers of a specific type, the grid laid out so an image can be focused on it. An astronomical photometer (as used for photometry in modern astronomy) may be such a CCD, aiming to catch all the photons in the image of 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)
Further reading:

Referenced by pages:
Large Altazimuth Telescope (BTA-6)
High Altitude Observatory (HAO)
Hubble Space Telescope (HST)
Mercator Telescope
Spitzer Space Telescope (SST)
2dF Galaxy Redshift Survey (2dFGRS)