Rotation and shell spectra among A-type dwarfs
Rotation and shell spectra among A-type dwarfs
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DOI：
10.1086/152184
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发表时间：
1973-06
期刊：
影响因子：
--
通讯作者：
H. Abt;K. Moyd
中科院分区：
文献类型：
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作者：
H. Abt;K. Moyd
给出了66颗金属线和123颗正常As-Ag IV或V星的自转速度，并用它们确定了赤道自转速度的频率分布。这些分布只有1.3%的重叠，这可能是因为这两个样本受到了轻微的污染。如果是这样的话，那么自转速度是一个必要且充分的参数来确定在特定的光谱类型和年龄范围内，恒星是否具有发达的金属线或正常光谱。在35颗自转速度最快的正常恒星中，有8颗被发现有壳层光谱。大多数壳星出现在恒星整体收缩期间或之后，此时恒星已经耗尽了大部分核心氢；其中一颗壳星显然最近收缩到了主序列。这些贝壳明星似乎是BE明星的A型配裤。(身份验证)
Rotational velocities for 66 metallic-line and 123 normal AS-Ag IV or V stars are given and used to determine the frequency distributions of equatorial rotational velocities. Those distributions have only a 1.3 percent overlap, which is probably due to a small contamination of the two samples. If so, then the rotational velocity is a necessary and sufficient parameter to detennine whether, within certain spectral type and age ranges, a star will have a well- developed metallic-line or normal spectrum. Among the 35 most rapidly rotating normal stars, eight were found to have shell spectra. Most of the shell stars occur during or just after the overall stellar contraction when the stars have depleted most of their core hydrogen; one shell star has apparently recently contracted to the main sequence. These shell stars seem to be the A-type counterpants of the Be stars. (auth)