Final answer:
Luminous objects emit their own light, like the Sun and standard candles used in astronomy, while non-luminous objects, such as the Moon and Earth, do not emit light and only reflect light from luminous sources. Luminosity is an object's intrinsic brightness, central to astronomy for measuring distances and characterizing celestial bodies.
Step-by-step explanation:
Difference Between Luminous and Non-Luminous Objects
The primary difference between luminous and non-luminous objects is that luminous objects emit their own light, while non-luminous objects do not emit light themselves and must reflect light from luminous sources to be visible. An example of a luminous object is the Sun, which produces its own light through nuclear reactions at its core, and a standard candle in astronomy, which is a type of astronomical object with a known luminosity that can be used as a reference to measure distances across the universe. In contrast, the Moon is an example of a non-luminous object as it only reflects the light from the Sun, and the Earth is another example since it too reflects sunlight.
Understanding the concept of luminosity is crucial for astronomers when analyzing celestial distances and the characteristics of stars, as well as when classifying objects based on inherent brightness versus their apparent brightness. Luminosity refers to the intrinsic brightness of an object — its true energy output — whereas apparent brightness is how bright an object appears to an observer on Earth. For instance, distant galaxies and celestial objects like supernovae can act as standard candles to help astronomers measure vast distances.