Brightness defined in more detail Brightness is described and measured in terms of radiant flux received from a celestial object. Radiant flux is the total amount of light energy (joules) that crosses one square meter per second. Radiant flux, F, is measured in watts. Radiant flux received from an object depends both on its distance, and on its luminosity. Luminosity is a measure of how much energy an object emits per second.
Magnitudes and Distance Measurement Discipline: Education This guide describes magnitude, distance modulus and distance measurement. These concepts are central to understanding distances and scale in the universe. You will find that the text contains many links. Some will take you to a glossary definition, while others are links to more information about a topic you may want to explore further. Please use this guide in the way that makes most sense to you. You may want to read the entire guide first, then go back and follow links that interest you, or you may want to follow links as you go along. Tags: scalefluxbrightness