# Astronomy Calculators

 Magnitude   Determines brightness, luminosity, apparent and absolute magnitude. Advanced Magnitude Calculator   Distance, Luminosity, Apparent and Absolute Magnitude - if you know two, this calculates the other two. Kepler's 3rd Law   Calculator for rudimentary T²=R³ computations. Kepler's 3rd Law Advanced Calculator   This allows mass to be brought into the T²=R³ equation. Escape Velocity Ultra Calculator   Calculates escape velocity and surface gravity. Synodic Period Calculator   Calculates synodic period. Mass Luminosity Relationship   Tutorial explaining how a star's mass affects its luminosity as well as its radius, temperature, longevity, spectral type and color. Solar Eclipses   Explains solar eclipses. A tutorial about opposition, conjunction, quadrature and synodic period is located here. Scale of the Universe  A listing of celestial objects (by length or distance), starting with the Earth, with each "step" ten times larger than the previous one. Twenty "steps" take you from the diameter of the Earth (12,800,000 meters) to the most distant galaxy ever observed (127,000,000,000,000,000,000,000,000 meters). Angular Size Calculator   Accurate for angles up to 180 degrees. The 88 Constellations   A listing of all 88 constellation names, descriptions and discoverers. Solar System Calculator   For use in calculating a solar system model to scale. Naked Eye Stars Dimmer Than The Sun   42 Stars that have an Absolute Magnitude higher than 4.85 "Supermoon" explanation   why the Full Moon's apparent size can vary.