2000/01/28 by Carlos Allende Prieto, David L. Lambert · 31 citations
Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Astrophysics and Star Formation Studies #Homogeneous #Metallicity #Optics #Parallax #Physics #Spectral line #Stars #Stellar, planetary, and galactic studies #Surface gravity #Ultraviolet #Wavelength #astro-ph
paper · pdf · doi:10.1086/301340
published in The Astronomical Journal 119(5), 2445-2454 (Institute of Physics) · 22 pages, 8 figures; an AASTeX v5.0 LaTeX2e document; uses graphicx.sty (included); to appear in the Astronomical Journal
arxiv created 2000/01/28 · openalex publication_date 2000/05/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Analyses of the near-ultraviolet continuum of late-type stars have led to controversial results regarding the performance of state-of-the-art model atmospheres. The release of the homogeneous International Ultraviolet Explorer ( IUE ) final archive and the availability of the high-accuracy Hipparcos parallaxes provide an opportunity to revisit this issue, as accurate stellar distances make it possible to compare observed absolute fluxes with the predictions of model atmospheres. The near-UV continuum is highly sensitive to T eff and [Fe/H], and once the gravity is constrained from the parallax, these parameters may be derived from the analysis of low-dispersion, long-wavelength (2000–3000 Å) IUE spectra for stars previously studied by Alonso, Arribas, & Martínez-Roger using the Infrared Flux Method (IRFM). A second comparison is carried out against the stars spectroscopically investigated by Gratton, Carretta, & Castelli. It is shown that there is a good agreement between T eff values obtained from the IRFM and those from the near-UV continuum, and a remarkable correspondence between observed and synthetic fluxes for stars with 4000 K ≤ T eff ≤ 6000 K of any metallicity and gravity. These facts suggest that model atmospheres provide an adequate description of the near-UV continuum forming region and that the opacities involved are essentially understood.