Blue stragglers in open clusters ? III. NGC 7789
Blue stragglers in open clusters ? III. NGC 7789
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DOI：
10.1051/0004-6361:20000213
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发表时间：
2001-02
影响因子：
6.5
通讯作者：
D. Schönberner;S. Andrievsky;J. Drilling
中科院分区：
文献类型：
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作者：
D. Schönberner;S. Andrievsky;J. Drilling
我们首次对中等年龄疏散星团NGC 7789中的蓝离散星样本进行了详细的LTE光谱研究。对其中8颗恒星，测定了若干元素的参数和丰度。星团成员表现出明显的表面镁倾向，这在B星晚期- a星早期是很不寻常的。铁和钛的丰度与NGC 7789金属丰度的其他光度和光谱估计一致。所有确认的蓝离散星都有相当低的预计旋转速度（除了K88一个例外，v sini = 80 km s 1）。
We performed for the rst time a detailed LTE spectroscopic study of a sample of blue straggler stars in the moderately old open cluster NGC 7789. For eight stars the parameters and abundances of several elements were determined. The cluster members show a remarkable surface magnesium deciency which is quite unusual for late B - early A stars. Iron and titanium abundances are in agreement with other photometric and spectroscopic estimates of the NGC 7789 metallicity. All the conrmed blue stragglers have rather low projected rotational velocities (with one exception for K88, v sini =8 0 km s 1 ).