An Etymological Dictionary of Astronomy and Astrophysics

Ultraviolet emission from an object in excess of that expected for a reference.
For example, → subdwarf stars show ultraviolet excess with respect to that expected from a star with → solar metallicity
at a given → effective temperature. In this case, UV excess results from smaller → line blanketing in
→ population II stars.

See also: → ultraviolet; → excess.