Spectral analysis of the extreme helium star LSS3184

Spectral analysis of the extreme helium star LSS3184
复制标题

极端氦星LSS3184的光谱分析

DOI：
--
复制
发表时间：
1998
期刊：
影响因子：
--
通讯作者：
U. Heber
U. Heber
中科院分区：
--
文献类型：
--
作者：
J. Drilling;C. S. Jeffery;U. Heber

文献摘要

被引文献

相似文献

抽象的。LSS3184是一种不含氢的fi早期B型手枪，最近发现它的脉动周期为2.5h。用fi-Ne分析的方法，从光学高分辨率光谱中提取了其热层参数。其主要结果为：Tef=23300 K，Logg=3.35，n H/n He&lt；∼0.00015，n C/n He=0.003，n N/n He=0.0005，n O/n He=0.0003。氢气是非常缺乏fi的。有效温度与宽带可见光谱、紫外光谱和消光系数E B−V∼0.2 7一致。它之前的进化反映在大气的化学中，大气中含有CNO循环氢燃烧产生的富氮和3α氦燃烧产生的碳。因此，examined.Keywords:stars:helium–individual(LSS3184)–abundances–3184是一颗真正的极氦恒星，其组成类似于BD−9◦4395。由于LSS3184的Tef、Logg和脉动性质非常类似于贫碳和富N的氦星V652，导致这两颗恒星表面成分截然不同的演化机制一定是LSS3184化学上特殊的发射线：Be1。前言恒星LSS3184是在OB的光谱测量中通过钻探(未发表)发现是氢fi的
Abstract. LSS3184 is a hydrogen-deficient, early B-type gi-ant, recently found to pulsate with a period of 2.5 hours. Itsphotospheric parameters have been derived from optical high-resolution spectra by the method of fine analysis. The principalresults are T eff = 23300 K, logg =3.35, n H /n He < ∼ 0.00015,n C /n He =0.003, n N /n He =0.0005, and n O /n He =0.0003.Hydrogen is extremely deficient. The effective temperature isconsistent with broad-band visual and ultraviolet spectropho-tometry and an extinction E B−V ∼ 0.27. Its previous evolutionis reflected in the chemistry of the atmosphere, which containsenriched nitrogen from CNO-cycle hydrogen burning, and car-bon from 3α helium burning. Thus LSS3184 is a true extremehelium star with a composition similar to BD−9 ◦ 4395.With T eff ,logg,andpulsationpropertiesverysimilartotheC-poor and N-rich helium star V652Her, evolutionary mecha-nisms which can result in very different surface compositionsfor the two stars must be examined.Keywords:stars:helium–individual(LSS3184)–abundances– chemically peculiar – emission line: Be1. IntroductionThe star LSS 3184 was found to be hydrogen-deficient byDrilling (unpublished) during a spectroscopic survey of OB