A METHOD FOR QUANTITATIVE DETECTION OF HOT HORIZONTAL BRANCHES IN EARLY-TYPE GALAXIES

Surface brightness fluctuation magnitudes in the 2800-4000 angstrom re gion are calculated. They show that a hot main sequence can be easily distinguished from a hot horizontal branch due the relative sensitivit y of fluctuation magnitudes to the presence of giants. Superluminous p ost-asymptotic giant branch (PAGB) stars will need to be subtracted be fore applying this method, and other hypothesized late-stage, hot star s may also contribute to the surface brightness fluctuation magnitudes , complicating the analysis. Application of this method further in the UV will provide an estimate of the luminosity of the next most lumino us subpopulation of stars after the PAGB stars, which will constrain t he possible populations responsible for the UV flux in ellipticals.