• DOI:10.1051/0004-6361/200811147
• Corpus ID: 14969137

Fundamental parameters of B supergiants from the BCD system I. Calibration of the (λ1, D) parameters into Teff

@article{Zorec2009FundamentalPO,
  title={Fundamental parameters of B supergiants from the BCD system I. Calibration of the ($\lambda$1, D) parameters into Teff},
  author={Juan Zorec and L. S. Cidale and Mar{\'i}a Laura Arias and Yves Fr{\'e}mat and Mar{\'i}a Florencia Muratore and Andrea F. Torres and Christophe Martayan},
  journal={Astronomy and Astrophysics},
  year={2009},
  volume={501},
  pages={297-320}
}

• J. Zorec, L. Cidale, +4 authors C. Martayan
• Published 30 March 2009
• Physics
• Astronomy and Astrophysics

Context. Effective temperatures of early-type supergiants are important to test stellar atmosphere- and internal structure-models of massive and intermediate mass objects at different evolutionary phases. However, these Teff values are more or less discrepant depending on the method used to determine them. Aims. We aim to obtain a new calibration of the Teff parameter for early-type supergiants as a function of observational quantities that are: a) highly sensitive to the ionization balance in the photosphere and its gas pressure; b) independent of the interstellar extinction; c) as much as possible model-independent. Methods. The observational quantities that best address our aims are the (λ1,D) parameters of the BCD spectrophotometric system. They describe the energy distribution around the Balmer discontinuity, which is highly sensitive to Teff and log g. We perform a calibration of the (λ1,D) parameters into Teff using effective temperatures derived with the bolometric-flux method for 217 program stars, whose individual uncertainties are on average |ΔTeff|/T f eff = 0.05. Results. We obtain a new and homogeneous calibration of the BCD (λ1,D) parameters for OB supergiants and revisit the current calibration of the (λ1,D) zone occupied by dwarfs and giants. The final comparison of calculated with obtained Teff values in the