luminosity

[ loo-muh-nos-i-tee ]

noun

, plural lu·mi·nos·i·ties.

1. luminance ( def 2 ).
2. the quality of being intellectually brilliant, enlightened, inspired, etc.:

   The luminosity of his poetry is unequaled.

3. something luminous.
4. Astronomy. the brightness of a star in comparison with that of the sun: the luminosity of Sirius expressed as 23 indicates an intrinsic brightness 23 times as great as that of the sun.
5. Also called luminosity factor. Optics. the brightness of a light source of a certain wavelength as it appears to the eye, measured as the ratio of luminous flux to radiant flux at that wavelength.

luminosity

/ ˌluːmɪˈnɒsɪtɪ /

noun

1. the condition of being luminous
2. something that is luminous
3. astronomy a measure of the radiant power emitted by a star
4. physics the attribute of an object or colour enabling the extent to which an object emits light to be observed Former namebrightness See also colour

Other Words From

• nonlu·mi·nosi·ty noun
• self-lumi·nosi·ty noun

Word History and Origins

Origin of luminosity¹

1625–35; < Latin lūminōs ( us ) luminous + -ity

Example Sentences

The annual Perseid meteor shower requires us to leave behind our light-polluted cities for darker night skies that allow us to see the full luminosity of the celestial attraction.

From Los Angeles Times

The discovery was made possible by the European Space Agency's Gaia spacecraft, which is mapping more than a billion stars throughout the Milky Way and beyond, tracking their motion, luminosity, temperature, and composition.

From Science Daily

The lower luminosities of red dwarf stars also means their habitable zones -- the range of orbital distances where liquid water could exist on a planet's surface -- lie closer to them.

From Science Daily

A quasar's extreme luminosity has been obvious since astronomers first discovered the objects in the 1960s.

From Science Daily

Lamps cannot be directed towards the upper hemisphere, and the law regulates their luminosity and color spectrum.

From Salon