Luminosity refers to the total amount of energy emitted by a star, galaxy, or other astronomical object per unit of time. It is often measured in watts or in terms of the Sun's luminosity, denoted as L☉. Luminosity helps astronomers understand the size, temperature, and distance of celestial bodies. In addition to its importance in astronomy, luminosity is also relevant in other fields, such as photography and lighting design. In these contexts, it describes the brightness of a light source or the intensity of light reflected from a surface, influencing how we perceive colors and details in images.