In astronomy, limiting magnitude is the faintest apparent magnitude of a celestial body that is detectable or detected by a given instrument.
In some cases, limiting magnitude refers to the utter threshold of detection. In more formal uses, limiting magnitude is specified along with the strength of the signal (e.g., "10th magnitude at 20 sigma"). Sometimes limiting magnitude is qualified by the purpose of the instrument (e.g., "10th magnitude for photometry") This statement recognizes that a photometric detector can detect light far fainter than it can reliably measure it.
The International Dark-Sky Association has been vocal in championing the cause of reducing skyglow and light pollution.
Read more about Limiting Magnitude: In Amateur Astronomy, Calculating Limiting Magnitude
Famous quotes containing the words limiting and/or magnitude:
“A way of certifying experience, taking photographs is also a way of refusing it—by limiting experience to a search for the photogenic, by converting experience into an image, a souvenir. Travel becomes a strategy for accumulating photographs.”
—Susan Sontag (b. 1933)
“War is pillage versus resistance and if illusions of magnitude could be transmuted into ideals of magnanimity, peace might be realized.”
—Marianne Moore (1887–1972)