EC 11481-2303 - A Peculiar Subdwarf OB Star Revisited
Abstract
EC 11481-2303 is a peculiar, hot, high-gravity pre-white dwarf. Previous optical spectroscopy revealed that it is a sdOB star with an effective temperature (Teff) of 41790 K, a surface gravity log(g)= 5.84, and He/H = 0.014 by number. We present an on-going spectral analysis by means of non-LTE model-atmosphere techniques based on high-resolution, high-S/N optical (VLT-UVES) and ultraviolet (FUSE, IUE) observations. We are able to reproduce the optical and UV observations simultaneously with a chemically homogeneous NLTE model atmosphere with a significantly higher effective temperature and lower He abundance (Teff = 55000 K, log (g) = 5.8, and He / H = 0.0025 by number). While C, N, and O appear less than 0.15 times solar, the iron-group abundance is strongly enhanced by at least a factor of ten.
Keywords
Cite
@article{arxiv.1001.5115,
title = {EC 11481-2303 - A Peculiar Subdwarf OB Star Revisited},
author = {T. Rauch and K. Werner and J. W. Kruk},
journal= {arXiv preprint arXiv:1001.5115},
year = {2015}
}
Comments
8 pages, 11 figures