Proceedings - Viện Vật lý

_________________________________________________________________________________Những tiến bộ trong Quang học, Quang tử, Quang phổ và Ứng dụng. 8/2006, Cần Thơ, Việt Nam2. Observation and spectral analysisWe collect high resolution (R~65000) and high signal to noise (S/N~1000)spectra using the spectropolarimeter ESPADONS on August 24, 2005. The spectraspan the entire optical domain from 370 nm to 1000 nm. The spectra are extractedand calibrated using the automatic reduction package LIBRE-ESPRIT (Donati et al)Radial velocity of 89 Herculis and HD 187885 are determined from thewavelength shift of many absorption lines of C, Fe and Cr. We find a heliocentricvelocity of -22 km/s for 89 Herculis and 18 km/s for HD 187885, respectively.The photospheric parameters Teff (effective temperature), surface gravity (log g),Table. 1. Elemental abundances of 89 Herculis and HD 187885Element89 Herculis [X/H] HD 187885 [X/H](Teff=7200 K, log g=1,Vt=4 km/s)(Teff=8000 K, log g=1,Vt=5 km/s)C -0.25 0.52N -0.31 0.62O -0.41 0.42Na -0.04 0.15Mg -0.22 -0.16Al -0.72 -0.56Si 0.01 0.23S 0 0.22Ca -0.7 -0.03Sc -0.51 -0.02Ti -0.82 -0.4Cr -0.32 -0.43Mn -0.27 -0.76Fe -0.48 -0.41Zn -0.26 -0.26Y -0.36 0.83Zr -0.67 0.69Ba -0.54 0.87La -0.99 0.22Ce -0.9 0.02Nd -0.66Sm -0.36Eu -0.51 -0.41Gd 1.02274