THE IRON ABUNDANCE OF IOTA-HERCULIS

We have obtained coadded, high-resolution IUE spectra of Iota Herculis (B3 IV) in both the short-wavelength (SWP) and long-wavelength (LWP) regions. LTE synthetic spectra with a resolution identical to that of IUE were produced with the Kurucz model atmosphere and spectral synthe sis codes ATLAS9/SYNTHE. Model parameters were chosen from the literat ure: T-eff=17,500 K, log g=3.75, upsilon sin i=11 km s(-1), and upsilo n(turb)=0 km s(-1). The abundance indicators were 48 lines of Fe II an d 26 lines of Fe III whose atomic parameters have been measured in the laboratory. Using a method that compares synthetic equivalent widths with observed ones, we find that the abundances derived from the diffe rent ionization stages are in agreement: both Fe II and Fe III lines y ield an abundance of [Fe/H]=-0.47+/-0.13 relative to the Sun. A curve of growth analysis yields similar results. Due to our choice of a zero microturbulent velocity, these results are upper limits, and we concl ude that Iota Herculis is significantly underabundant in iron relative to the Sun.