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:
“O wily painter, limiting the scene
From a cacophony of dusty forms
To the one convulsion,”
—Thom Gunn (b. 1929)
“My time has come.
There are twenty people in my belly,
there is a magnitude of wings,
there are forty eyes shooting like arrows,
and they will all be born.
All be born in the yellow wind.”
—Anne Sexton (1928–1974)