radiant

Short definition from Wiktionary

Adjective

1. 1
   Radiating light and/or heat.
2. 2
   Emitted as radiation.
3. 3
   Beaming with vivacity and happiness.
4. 4
   Strikingly beautiful.
5. 5
   Emitting or proceeding as if from a center.
6. 6
   Giving off rays.
7. 7
   Having a ray-like appearance, like the large marginal flowers of certain umbelliferous plants; said also of the cluster which has such marginal flowers.

Noun

1. 1
   A point source from which radiation is emitted.
2. 2
   The apparent origin, in the night sky, of a meteor shower.
3. 3
   A straight line proceeding from a given point, or fixed pole, about which it is conceived to revolve.