Blue horizontal branch stars in M92

被引:36
作者
Cohen, JG
McCarthy, JK
机构
[1] Palomar Observatory, California Institute of Technology, Pasadena, CA 91125
关键词
D O I
10.1086/118348
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We have analyzed high dispersion and high precision spectra of 5 blue horizontal branch stars in the globular cluster M92 to establish that the projected rotational velocity for these stars ranges from 15 to 40 km s(-1). This is larger than that expected based on the rotation of their main sequence progenitors, the spin down of rotation with age, and the conservation of angular momentum. Possible explanations include a rapidly rotating stellar core. An abundance analysis of these spectra of these blue HE stars in M92 yields the same results as have been obtained from the giants in this cluster. There is a hint of a trend of higher abundance as the projected surface rotational velocity increases, which could be chance and requires confirmation. (C) 1997 American Astronomical Society.
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页码:1353 / 1358
页数:6
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