The overall brightness of an extended astronomical object such as a galaxy, star cluster, or nebula, can be measured by its total magnitude, integrated magnitude or integrated visual magnitude; a related concept is surface brightness, which specifies the brightness of a standard-sized piece of an extended object.
Famous quotes containing the words surface and/or brightness:
“In the cold of Europe, under prudish northern fogs, except when slaughter is afoot, you only glimpse the crawling cruelty of your fellow men. But their rottenness rises to the surface as soon as they are tickled by the hideous fevers of the tropics.”
—Louis-Ferdinand Céline (18941961)
“on thy brow
Shall sit a nobler grace than now.
Deep in the brightness of the skies
The thronging years in glory rise.
And, as they fleet,
Drop strength and riches at thy feet.”
—William Cullen Bryant (17941878)