a classification of stars of a given spectral type according to their luminosity, breaking them down into dwarfs, giants, and supergiants.
[loo-muh-nuh s] /ˈlu mə nəs/ adjective 1. radiating or reflecting light; shining; bright. 2. lighted up or illuminated; well-lighted: the luminous ballroom. 3. brilliant intellectually; enlightened or enlightening, as a writer or a writer’s works: a luminous concept; luminous prose. 4. clear; readily intelligible: a concise, luminous report. /ˈluːmɪnəs/ adjective 1. radiating or reflecting light; […]
noun, Optics. 1. the perceived brightness of light as a ratio of the total luminous flux to total radiant flux of the source; a measure of brightness obtained by dividing the source’s luminous flux by the consumption of its energy. noun 1. the efficiency of polychromatic radiation in producing a visual sensation. It is the […]
noun, Optics. 1. luminous flux emitted per unit area.
noun 1. 1 (def 2a). noun 1. energy emitted or propagated in the form of light; the product of a luminous flux and its duration, measured in lumen seconds Qv