Radiance (noun)

1. The quality of being bright and sending out rays of light.
2. The quality of being full of happiness and contentment.
3. The state of emitting radiant energy.

Origin:

Late middle english: from old french radiance, from latin radiantia, from radians, present participle of radere "shine", from radius "ray".

Examples:

1. The sun's radiance was so bright that she had to squint her eyes.
2. She had a radiance about her that made everyone feel better just being around her.
3. The radiance of the star was measured by the telescope.
4. The radiance of the diamond was breathtaking.
5. The radiance of the smile on her face was contagious.