Three Li-rich K Giants: IRAS 12327−6523, 13539−4153, and 17596−3952
Three Li-rich K Giants: IRAS 12327−6523, 13539−4153, and 17596−3952
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DOI：
10.1086/430190
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发表时间：
2005-03
期刊：
影响因子：
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通讯作者：
B. E. Reddy;D. Lambert
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文献类型：
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作者：
B. E. Reddy;D. Lambert
我们报告了三颗K巨星的光谱分析结果，这三颗K巨星以前被认为是富锂的：IRAS 12327-6523，13539-4153和17596-3952。高分辨率的光谱和LTE模型大气被用来推导恒星参数（Teff，log g，[Fe/H]），元素丰度，和同位素比12 C/13 C。IRAS 13539-4153显示出极高的锂丰度，log [Li]= 4.2，比当地星际介质中目前的锂丰度高出10倍。这是迄今为止关于K巨星的第三高的Li丰度。IRAS 12327-6523显示Li丰度为log Li（Li）= 1.4。IRAS 17596-3952是一颗快速自转的K巨星（V sin i = 35 km s-1），log ψ（Li）= 2.2。红外光度法显示存在IR过量，表明质量损失。比较这三颗恒星和以前公认的富锂巨星。
We report on spectroscopic analyses of three K giants previously suggested to be Li-rich: IRAS 12327-6523, 13539-4153, and 17596-3952. High-resolution optical spectra and the LTE model atmospheres are used to derive the stellar parameters (Teff, log g, [Fe/H]), elemental abundances, and the isotopic ratio 12C/13C. IRAS 13539-4153 shows an extremely high Li abundance of log ϵ(Li) ≈ 4.2, a value 10 times greater than the present Li abundance in the local interstellar medium. This is the third highest Li abundance yet reported for a K giant. IRAS 12327-6523 shows a Li abundance of log ϵ(Li) ≈ 1.4. IRAS 17596-3952 is a rapidly rotating (V sin i ≈ 35 km s-1) K giant with log ϵ(Li) ≈ 2.2. Infrared photometry shows the presence of an IR excess, suggesting mass loss. A comparison is made between these three stars and previously recognized Li-rich giants.