Primary Light Source
A surface or object emitting light which is produced by a transformation of energy. The surface or object may at the same time emit invisible radiation.
Reference: C.I.E. (modified)
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)
Celsius (previously Centigrade)
International Association of Marine Aids to Navigation and Lighthouse Authorities - AISM