EDP Sciences
Free Access
Volume 382, Number 3, February II 2002
Page(s) 999 - 1004
Section Formation, structure and evolution of stars
DOI https://doi.org/10.1051/0004-6361:20011703

A&A 382, 999-1004 (2002)
DOI: 10.1051/0004-6361:20011703

On the effective temperature scale of O stars

F. Martins1, D. Schaerer1 and D. J. Hillier2

1  Observatoire Midi-Pyrénées, Laboratoire d'Astrophysique, 14 Av. E. Belin, 31400 Toulouse, France
2  Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260, USA

(Received 18 September 2001 / Accepted 16 November 2001 )

We rediscuss the temperature of O dwarfs based on new non-LTE line blanketed atmosphere models including stellar winds computed with the CMFGEN code of Hillier & Miller (1998). Compared to the latest calibration of Vacca et al. (1996), the inclusion of line blanketing leads to lower effective temperatures, typically by ~4000 to 1500 K for O3 to O9.5 dwarf stars. The dependence of the Teff-scale on stellar and model parameters - such as mass loss, microturbulence, and metallicity - is explored, and model predictions are compared to optical observations of O stars. Even for an SMC metallicity we find a non-negligible effect of line blanketing on the Teff-scale. The temperature reduction implies downward revisions of luminosities by ~0.1 dex and Lyman continuum fluxes Q0 by approximately 40% for dwarfs of a given spectral type.

Key words: stars: general -- stars: temperature -- stars: fundamental parameters -- stars: atmospheres

Offprint request: F. Martins, martins@ast.obs-mip.fr

SIMBAD Objects

© ESO 2002

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.