apparent magnitude

(redirected from Visual brightness)
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apparent magnitude:

see magnitudemagnitude,
in astronomy, measure of the brightness of a star or other celestial object. The stars cataloged by Ptolemy (2d cent. A.D.), all visible with the unaided eye, were ranked on a brightness scale such that the brightest stars were of 1st magnitude and the dimmest stars
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apparent magnitude

See magnitude.

apparent magnitude

[ə′pa·rənt ′mag·nə‚tüd]
(astronomy)
An index of a star's brightness relative to that of the other stars; it does not take into account the difference in distance between the stars and is not an indication of the star's true luminosity.
References in periodicals archive ?
One is a perceptual brilliance, involving visual brightness (including whiteness, iridescence, etc.).
Although its visual brightness normally varies by a factor of 140, the star's actual energy output only varies by a factor of two.
(The changing orientation of Uranus's rings does not affect the planet's visual brightness; ring orientation, however, can affect the brightness at some infrared wavelengths.)
Peltier was known for his observations of variable stars, making some 132,000 visual brightness estimates, and for his discovery of a dozen comets and two novae.
FU Orionis eruptions typically last many decades and may occur repeatedly in a given star, increasing its visual brightness by up to five or six magnitudes.
To monitor Algol more closely, make a visual brightness estimate every half hour for as many hours as possible spanning a predicted eclipse.
Thus, the drop in the nova's visual brightness does not necessarily indicate that its total brightness is declining -- only that we are now seeing through the outermost layers into deeper, hotter ones where a large fraction of the energy is being radiated in the ultraviolet.
After an initial rise that lasted only a few days, the visual brightness dimmed for a week and then rose to a second maximum about two weeks later!