In SI units, luminosity is measured in joules per second, or watts. In astronomy, values for luminosity are often given in the terms of the luminosity of the Sun, L⊙.

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Luminosity, in astronomy, the amount of light emitted by an object in a unit of time. The luminosity of the Sun is 3.846 × 1026 watts (or 3.846 × 1033 ergs per second).

luminosity noun lu· mi· nos· i· ty ˌlü-mə-ˈnä-sə-tē plural luminosities Synonyms of luminosity 1 a : the quality or state of being luminous

2025年8月28日 · Luminosity is the total energy emitted by a celestial object per unit of time from its surface. It radiates across the entire electromagnetic spectrum. Unlike apparent brightness, …

2026年3月18日 · Luminosity is a key concept in astronomy that measures the total amount of energy a celestial object—such as a star, galaxy, or nebula—emits per second. Unlike apparent brightness, …

The luminosity of a star, on the other hand, is the amount of light it emits from its surface. The difference between luminosity and apparent brightness depends on distance.