2004/02/09 by Miriam Garcia, Luciana Bianchi · 1 citation
Physics and Astronomy · Social Sciences · #Astronomy and Astrophysical Research #Educational Leadership and Practices #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/383002
published as Astrophys.J. 606 (2004) 497-513 · Accepted for publication in The Astrophysical Journal. 38 pages (including 9 figures and 4 tables)
arxiv created 2004/02/09 · openalex publication_date 2004/04/20 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/01
We derived the stellar parameters of a sample of Galactic early-O type stars by analyzing their UV and far-UV spectra from the Far Ultraviolet Spectroscopic Explorer (905-1187 Å), the International Ultraviolet Explorer , the Hubble Space Telescope STIS, and the Orbiting and Retrievable Far and Extreme Ultraviolet Spectrometer (1200-2000 Å). The data have been modeled with spherical, hydrodynamic, line-blanketed, non-LTE synthetic spectra computed with the WM-BASIC code. We obtain effective temperatures ranging from T eff = 41,000 to 39,000 K for the O3-O4 dwarf stars and T eff = 37,500 K for the only supergiant of the sample (O4 If + ). Our values are lower than those from previous empirical calibrations for early-O types by up to 20%. The derived luminosities of the dwarf stars are also lower by 6%-12%; however, the luminosity of the supergiant is in agreement with previous calibrations within the error bars. Our results extend the trend found for later O types in a previous work by Bianchi & Garcia.