AUREOLE
[noun]
1. a radiance surrounding the head or the whole figure in the representation of a sacred personage.
2. any encircling ring of light or colour; halo.
3. Astronomy: corona; a white or coloured circle or set of concentric circles of light seen around a luminous body, especially around the sun or moon.
4. Geology: a zone of altered country rock around an igneous intrusion.