The sun, a celestial body, emits immense luminous flux, a measure of light emitted, and has a luminosity of approximately 3.828 × 10^26 lumens. This extraordinary output results from the sun’s nuclear fusion reactions, releasing vast amounts of energy as solar radiation. Irradiance, measuring the power of light reaching a given area, is high near the sun and decreases with distance. Illuminance, quantifying light falling on a surface, varies depending on factors such as distance, time of day, and atmospheric conditions. Understanding these photometric concepts and their significance in astronomy helps us comprehend the sun’s role in our solar system and beyond.
