HD 161701, a chemically peculiar binary with a HgMn primary and an Ap secondary
HD 161701, a chemically peculiar binary with a HgMn primary and an Ap secondary
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DOI：
10.1051/0004-6361/201322327
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发表时间：
2014
影响因子：
6.5
通讯作者：
J. F. González;C. Saffe;F. Castelli;S. Hubrig;I. Ilyin;M. Schöller;T. Carroll;F. Leone;M. Giarrusso
中科院分区：
文献类型：
--
作者：
J. F. González;C. Saffe;F. Castelli;S. Hubrig;I. Ilyin;M. Schöller;T. Carroll;F. Leone;M. Giarrusso
上下文近年来，HgMn星引起了人们的广泛关注，在其中几颗星上发现了不同元素的表面化学斑点，但其起源以及与双星和磁场的可能联系尚不清楚。目标。本文对HgMn双星HD 161701进行了全面的研究，包括物理参数和光球化学丰度的测定。方法.我们分析了ESO的光谱仪FEROS和光谱偏振仪HARPS获得的高分辨率光谱观测的时间序列，以及CRIRES获得的近红外光谱。两颗恒星的径向速度曲线与额外的光谱信息相结合，以估计绝对恒星参数。光谱分离技术的应用，使我们能够进行详细的光谱分析的HgMn的主要和低光度的次要成分，这原来是一个特殊的星星以及。通过光谱合成确定化学丰度。使用HARPS和FEROS光谱在11个旋转阶段，我们检测到线轮廓的变化，在两个恒星的同伴，表明不均匀的表面分布的化学成分。结果HD 161701是一个由两颗化学性质特殊的恒星组成的双星系统，它们在一个周期为12.451 d的近圆形轨道上运行。
Context. In recent years, HgMn stars have attracted attention after in several of them surface chemical spots of different elements were discovered, whose origin and possible connection with binarity and magnetic fields is not clear yet. Aims. We perform a complete study of the HgMn binary HD 161701, including the determination of physical parameters and photospheric chemical abundances. Methods. We analyzed time series of high-resolution spectroscopic observations obtained with ESO’s spectrograph FEROS and the spectro-polarimeter HARPS, in addition to a near-IR spectrum obtained with CRIRES. Radial velocity curves for both stars were combined with additional spectroscopic information to estimate absolute stellar parameters. A spectral separation technique was applied, which enabled us to conduct a detailed spectral analysis of both the HgMn primary and the low-luminosity secondary component, which turned out to be a peculiar star as well. Chemical abundances were determined by spectral synthesis. Using HARPS and FEROS spectra obtained at 11 rotational phases, we detected line profile variations in both stellar companions, indicating a nonuniform surface distribution of chemical composition. Results. HD 161701 is a binary system formed by two chemically peculiar stars in an almost circular orbit with a period of 12.451 d.