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."

Definitions of luminosity

n the quality of being luminous; emitting or reflecting light

“its luminosity is measured relative to that of our sun”
brightness, brightness level, light, luminance, luminousness
illuminance, illumination
the luminous flux incident on a unit area
light from heat
glow, luminescence
light from nonthermal sources
Type of:
physical property
any property used to characterize matter and energy and their interactions

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