Reddenings of FGK supergiants and classical Cepheids from spectroscopic data
Reddenings of FGK supergiants and classical Cepheids from spectroscopic data
复制标题
光谱数据中 FGK 超巨星和经典造父变星的红化
DOI：
10.1111/j.1365-2966.2008.13644.x
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发表时间：
2008
影响因子：
4.8
通讯作者：
F. Chekhonadskikh
中科院分区：
文献类型：
--
作者：
V. Kovtyukh;C. Soubiran;R. E. Luck;D. Turner;S. I. Belik;S. Andrievsky;F. Chekhonadskikh
Accurate and homogeneous atmospheric parameters (T eff , log g, V t , [Fe/H]) are derived for 74 FGK non-variable supergiants from high-resolution, high signal-to-noise ratio, echelle spectra. Extremely high precision for the inferred effective temperatures (10-40K) is achieved by using the line-depth ratio method. The new data are combined with atmospheric values for 164 classical Cepheids, observed at 675 different pulsation phases, taken from our previously published studies. The derived values are correlated with unreddened B - V colours compiled from the literature for the investigated stars in order to obtain an empirical relationship of the form (B - V) o = 57.984 - 10.3587(log T eff ) 2 + 1.67572(logT eff ) 3 - 3.356 log g + 0.0321V t + 0.2615[Fe/H] + 0.8833(logg)(logTeff). The expression is used to estimate colour excesses E(B - V) for individual supergiants and classical Cepheids, with a precision of ±0.05 mag for supergiants and Cepheids with n = 1-2 spectra, reaching ±0.025 mag for Cepheids with n > 2 spectra, matching uncertainties for the most sophisticated photometric techniques. The reddening scale is also a close match to the system of space reddenings for Cepheids. The application range is for spectral types FO-KO and luminosity classes I and II.
