Is the lightning non luminous or luminous?

Objects that give out light of their own are said to be luminous such as the sun, stars, fireflies, glowworms and some deep sea fish etcObjects that do not give out light of their own are said to be...

luminous - emits light e.g. the sun non- luminous - does not emit light though will often reflect light e.g. the moon.

Luminous

Our sun actually is a star so yes, stars are luminous. The produce huge amounts of light and heat through nuclear fusion of hydrogen.

All things, except black holes, are luminous. That includes stars. You might think that some other things are not luminous but that's because you can't see the kinds of light that they emit.