EC 11481-2303: A peculiar hot high-gravity pre-white dwarf

We report the discovery of a peculiar new hot high-gravity predegenerate st ar, EC 11481 - 2303 from the Edinburgh-Cape Blue Object Survey, based upon the analysis of far-UV International Ultraviolet Explorer (IUE) echelle and low-resolution spectra and an optical spectrum. The IUE spectra reveal the presence of far-UV photospheric/circumstellar high-ionization absorption f eatures due to N V lambda lambda 1238, 1242, Si IV lambda lambda 1393, 1402 , C IV lambda lambda 1548, 1550, and He II lambda 1640. The mean velocity o f these features is - 17.5 km s(-1). In addition, there is low-ionization i nterstellar absorption at an average velocity of - 5.6 km s(-1). The inters tellar lines are strong and imply a distance of more than 500 pc. The optic al spectrum is dominated by Stark-broadened Balmer absorption, a sharp He I I lambda 4686 feature, and the absence of Balmer members higher than H8. A best-fit model atmosphere to the optical data yields T-eff = 41,790 K and l og g = 5.84, suggesting an extended horizontal branch sdOB subdwarf. Howeve r, synthetic spectral fits to the far-UV spectrum do not provide a consiste nt fit to both the Ly alpha region and the far-UV continuum of EC 11481-230 3, It is possible that EC 11481-2303 is an unresolved binary. Follow-up gro und-based and far-UV studies are encouraged to discern the possible nature of any binary companion.