The late A-type stars - Refined MK classification, confrontation with Stromgren photometry, and the effects of rotation
The late A-type stars - Refined MK classification, confrontation with Stromgren photometry, and the effects of rotation
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晚期A型恒星——细化的MK分类、与Stromgren测光的对抗以及旋转的影响
DOI：
10.1086/191349
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发表时间：
1989
影响因子：
8.7
通讯作者：
R. Garrison
中科院分区：
文献类型：
--
作者：
R. Gray;R. Garrison
细化了晚期 A 型恒星的 MK 光谱分类，并检查了光谱分类旋转和 uvby(beta) 光度测量对这些恒星的影响。研究发现，对于 A3 星，4417/4481 A 波长比产生的结果与 H 线的斯塔克展宽不一致。建议该比率不能用作任何光谱类型的光度标准。建立了自洽的窄线和宽线标准序列。将精细分类系统的结果与 Stromgren 光度测量进行比较，显示一组低 v sin i A 型恒星，其光度类型具有异常大的 delta(c sub 1) 指数。有人认为这些恒星是在相当低的倾角下看到的快速旋转体。 24 参考文献
The MK spectral classification for late A-type stars is refined and the effects of rotation of spectral classification and uvby(beta) photometry for these stars are examined. It is found that, for A3 stars, the 4417/4481 A wavelength ratio produces results that are inconsistent with the Stark broadening of the H lines. It is suggested that this ratio is not useful as a luminosity criterion at any spectral type. Self-consistent sequences of narrow- and broadline standards are established. The results of the refined classification system are compared with Stromgren photometry, showing a set of low-v sin i A-type stars with anomalously large delta(c sub 1) indices for their luminosity types. It is proposed that these stars are rapid rotators seen at fairly low inclination angles. 24 refs.