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arXiv 2105.02206astro-ph.SR
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太阳质量抛射成像仪研究的磁性化学奇特星

Magnetic chemically peculiar stars investigated by the Solar Mass Ejection Imager

E. Paunzen, J. Supikova, K. Bernhard, S. Huemmerich, M. Prisegen

摘要:

自从1897年发现其原型α 2 Canum Venaticorum的光谱特性以来,所谓的ACV变星,由几组化学性质特殊的上主序星组成,一直是众多光度和光谱研究的目标。特别是对于较亮的ACV变星,可以进行大约一个世纪的连续观测,这对于研究这些天体的周期变化或磁循环等长期影响非常重要。利用太阳质量抛射成像仪(SMEI)在2003年至2011年期间获得的光变曲线,对165颗Ap/CP 2和He-weak/CP 4恒星进行了分析。这些数据填补了Hipparcos和TESS卫星任务之间明亮ACV变量观测的重要空白。使用专门定制的数据处理和周期搜索方法,我们发现84个对象中所采用的数据的准确性限制的变化。导出的周期与文献非常吻合;对于一颗恒星,这里提出的解决方案代表了第一次发表的周期。我们讨论了明显不变的恒星和相应的不变性水平。从我们的目标恒星样本的赫兹-罗素图的调查,我们推断年龄在1亿年和1 Gyr之间的大多数我们的样本恒星。我们的研究结果支持的变量CP 2/4星是在一个更先进的进化状态和他和Si的特点,优先发现在更热,因此更大的质量,CP星,产生更大的斑点或斑点的对比度更高。

英文摘要:

Since the discovery of the spectral peculiarities of their prototype alpha2 Canum Venaticorum in 1897, the so-called ACV variables, which are comprised of several groups of chemically peculiar stars of the upper main sequence, have been the target of numerous photometric and spectroscopic studies. Especially for the brighter ACV variables, continuous observations over about a century are available, which are important to study long-term effects such as period changes or magnetic cycles in these objects. The present work presents an analysis of 165 Ap/CP2 and He-weak/CP4 stars using light curves obtained by the Solar Mass Ejection Imager (SMEI) between the years 2003 and 2011. These data fill an important gap in observations for bright ACV variables between the Hipparcos and TESS satellite missions. Using specifically tailored data treatment and period search approaches, we find variability in the accuracy limit of the employed data in 84 objects. The derived periods are in excellent agreement with the literature; for one star, the here presented solution represents the first published period. We discuss the apparently constant stars and the corresponding level of non-variability. From an investigation of our target star sample in the Hertzsprung-Russell diagram, we deduce ages between 100 Myr and 1 Gyr for the majority of our sample stars. Our results support that the variable CP2/4 stars are in a more advanced evolutionary state and that He and Si peculiarities, preferentially found in the hotter, and thus more massive, CP stars, produce larger spots or spots of higher contrast.

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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