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arXiv 0812.3827astro-ph
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非食RS CVn型星色球层的长期活动

Long-term chromospheric activity of non-eclipsing RS CVn-type stars

Andrea P. Buccino, Pablo J. D. Mauas

摘要:

上下文IUE数据库提供了1978年至1996年大量的RS CVn型恒星的紫外高分辨率和低分辨率光谱。特别是,这些恒星中的许多都是由IUE在几个季节中连续监测的。目标。我们的主要目的是研究IUE观测最多的RS CVn系统:HD 22468(V711 Tau,HR 1099,K1 IV + G5 V),HD 21242(UX Ari,K 0 IV + G5 V)和HD 224085(II Peg,K2 IV)的色球层活动。方法.我们首先从IUE的高、低分辨率光谱中获得Mount Wilson指数S。其次,用Lomb-Scaggle周期图分析了年平均指数S及其旋转调制幅度。结果对于HD 22468(V711 Tau,HR 1099),我们发现了一个可能的18年周期的色球周期和一个3年周期的较短周期,这可能与色球“翻转”周期有关。HD 224085(II Peg)的数据还表明色球周期为21年,翻转周期为9年。最后,我们得到了HD 21242(UX Ari)可能的色球周期为7年。

英文摘要:

Context. The IUE database provides a large number of UV high and low-resolution spectra of RS CVn-type stars from 1978 to 1996. In particular, many of these stars were monitored continuously during several seasons by IUE. Aims. Our main purpose is to study the short and long-term chromospheric activity of the RS CVn systems most observed by IUE: HD 22468 (V711 Tau, HR 1099, K1IV+G5V), HD 21242 (UX Ari, K0IV+G5V) and HD 224085 (II Peg, K2IV). Methods. We first obtain the Mount Wilson index S from the IUE high and low-resolution spectra. Secondly, we analyse with the Lomb-Scargle periodogram the mean annual index S and the amplitude of its rotational modulation. Results. For HD 22468 (V711 Tau, HR 1099), we found a possible chromospheric cycle with a period of 18 years and a shorter cycle with a period of 3 years, which could be associated to a chromospheric "flip-flop" cycle. The data of HD 224085 (II Peg) also suggest a chromospheric cycle of 21 years and a flip-flop cycle of 9 years. Finally, we obtained a possible chromospheric cycle of 7 years for HD 21242 (UX Ari).

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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