The Collaborative International Dictionary of English v.0.48:
Luminary \Lu"mi*na*ry\, n.; pl. Luminaries, [F. luminaire, L.
luminare a light or lamp, which was lighted in the churches,
a luminary, fr. lumen, luminis, light, fr. lucere to be
light, to shine, lux, lucis, light. See Light.]
1. Any body that gives light, especially one of the heavenly
bodies. " Radiant luminary." --Skelton.
Where the great luminary . . .
Dispenses light from far. --Milton.
2. One who illustrates any subject, or enlightens mankind;
as, Newton was a distinguished luminary.