luminosity

American  

[loo-muh-nos-i-tee] / ˌlu məˈnɒs ɪ ti /

noun

• luminosities
  plural

1. luminance.

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 luminosity factor.  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.

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luminosity British  

/ 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. Former name: brightness.  physics the attribute of an object or colour enabling the extent to which an object emits light to be observed See also colour

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Other Word Forms

Derived Forms

• nonluminosity
  noun
• self-luminosity
  noun

Inflected Forms

Nouns

• luminosities
  plural

Etymology

Origin of luminosity

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

Explanation

Luminosity is the quality of something that gives off light or shines with reflected light. The most noticeable quality of a large, sparkly diamond is its luminosity. You might describe a bright and lively oil painting in terms of its luminosity, or marvel at the luminosity of a brilliant sunset. Astronomers use the word luminosity to talk about a specific property of physics, the energy given of by an astronomical object in a certain amount of time. There's a direct correlation between this amount of energy and the object's brightness. The Latin root is lumen, meaning "light."

Example Sentences

See Examples For:

luminosity luminosities

The goal is to increase the "luminosity" -- that is, the total number of collisions produced over a given period -- by a factor of 10 compared to the LHC.

From Barron's ● Jun. 27, 2026

By 2024, it reached a high luminosity, more than two orders of magnitude higher than in 2021.

From Science Daily ● Dec. 14, 2025

“I have no medium that can give me color of such wonderful luminosity as the Autochrome plate,” wrote the photographer Edward Steichen in 1908.

From The Wall Street Journal ● Nov. 21, 2025

The Guardian's three star review said his "words glitter with feeling" and added that he "singularly shines, his luminosity putting the others slightly in the shade".

From BBC ● Feb. 19, 2025

For nearby stars, we can measure their apparent brightness and their distance, and so we can work out their luminosity.

From "A Brief History of Time: And Other Essays" by Stephen Hawking

High-sensitivity observations have discovered objects with extremely high X-ray luminosities.

From Science Daily ● Dec. 14, 2025

"This allows us to help explain the extreme luminosities of active galactic nuclei as well as the acceleration of particles to nearly the speed of light."

From Science Daily ● Oct. 8, 2025

Suvi Gezari, an astronomer at the Space Telescope Science Institute, says the observations extend the phenomenon of red novae to much lower luminosities and into the regime of planetary engulfments.

From Science Magazine ● May 3, 2023

The brutal fury of a system like WR 140 is undeniable, from the incredible luminosities of its stars to the cosmic tsunami of dusty winds they blast away.

From Scientific American ● Oct. 25, 2022

The following are the luminosities for the colours fixed by the principal lines of the solar spectrum, and for the red and blue lines of lithium, to which reference has already been made.

From Colour Measurement and Mixture by W. de W. Abney