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 the context of stars, luminosity is influenced by factors such as temperature and surface area. Hotter stars emit more energy and appear brighter, while larger stars can also be more luminous. The relationship between luminosity and temperature is described by the Stefan-Boltzmann Law, which states that luminosity increases with the fourth power of temperature.