类太阳色球活动星εEri磁场的观测研究

AN OBSERVATION STUDY OF THE MAGNETIC FIELD ON THE SOLAR-LIKE CHROMOSPHERE ACTIVE STAR εERI

本文给出１９９３—１９９４年期间，用云南天文台１米望远镜折轴摄谱仪观测获得类太阳色球活动星。εＥｒｉ的５个波段高分辨、高信噪比光谱，运用两种不同方法：谱线轮廓塞曼致宽分析和多重线统计分析法成功地测定了εＥｒｉ的表面磁场强度和磁场的覆盖因子，并对这两种磁场测定方法作了简单的讨论．

CCD spectra of solar-like star εEri with High-resolution (△λ=0. 1A), high signal-to-noise ratio (S/N=100￣300) were obtained using Coude spectrograph of Yunnan Observatory from Feb. 1993 to Nov. 1994. In this paper, the preliminary results of determined magnetic field of εEri are presented. For which we used two methods which are' profile-addition-technique' of spectral profiles of Zeeman broadening and the Stenflo-Lindegren statistical analysis.1. profile-addition-technique of spectral profilesWe asstuned that a magnetic split line profile F(λ), can be represented by the weighted convolution of three unsplit line profiles, F0(λ). For a stellar atmosphere magnetic regions cover a fraction α of the surface. High-and low-g lines, 6173.34A (g=2.5) and 6240.65A (g=1.0) were selected.2. The Stenflo-Lindegren statistical analysisUsing the profiles of 29 lines of observation FeI in five wevelength bands, We have calculated FWHM and S(z) (z=0.5, 0.25, 0.2) of lines (see table 1).Our determination results of Magnetic field of εEri are as following,The method a(%)B(G)A. profile-addition-technique 0.49 2390B. statistical analysis 0.20 1881We summarized the recently published results of the magnetic field of εEri, and listed in the table 2.The brief description and discussion for two methods were made.