luminosity (n.)youdaoicibaDictYouDict[luminosity 词源字典]
1630s, "quality of being luminous," from French luminosité or else a native formation from luminous + -ity. In astronomy, "intrinsic brightness of a heavenly body" (as distinguished from apparent magnitude, which diminishes with distance), attested from 1906.[luminosity etymology, luminosity origin, 英语词源]