definition of absolute magnitude
â¢ ABSOLUTE MAGNITUDE (noun) The noun ABSOLUTE MAGNITUDE has 1 sense: 1. (astronomy) the magnitude that a star would have if it were viewed from a distance of 10 parsecs (32.62 light years) from the earth. Familiarity information: ABSOLUTE MAGNITUDE used as a noun is very rare. Dictionary entry details. â¢ ABSOLUTE MAGNITUDE (noun)