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:
“There could be no fairer destiny for any physical theory than that it should point the way to a more comprehensive theory in which it lives on as a limiting case.”
—Albert Einstein (1879–1955)
“We quaff the cup of life with eager haste without draining it, instead of which it only overflows the brim—objects press around us, filling the mind with their magnitude and with the throng of desires that wait upon them, so that we have no room for the thoughts of death.”
—William Hazlitt (1778–1830)