Some examples of luminous objects are a burning candle, a light bulb, the sun and other stars, fluorescent materials and tube lights, among other things. Any object is considered luminous if it emits its own light, either through stored energy or energy supplied to the object, which contrasts with non-luminous objects such as the moon, wood, plastics and metals; these objects merely reflect light instead of providing their own.
Luminous objects are responsible for our vision, as the human eye only perceives light that is being reflected into it. In darkness, where no luminous objects are present, the eye cannot perceive its surroundings.
In order for luminous objects to emit light, there must be a power source. The sun and other stars produce light due to the fusion of hydrogen atoms, the light bulb emits light due to the electrical energy flowing through it and the lit candle uses energy released by burning the wick. Fluorescent materials store energy given by other luminous objects and release light in wavelengths that cannot be seen in visible light. Some living organisms, such as fireflies, have natural luminescence, which allows them to convert the chemical energy stored in their cells into light. All luminous objects also release heat with the light they generate.