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arXiv 2001.08798astro-ph.SRastro-ph.EP
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四重系统HIP 45734

The quadruple system HIP 45734

Andrei Tokovinin

摘要:

HIP 45734是一个2+2结构的四重系统,位于距离太阳68 pc处。外9”系统A、B的周期约为10^4年。双星对Aa,Ab是一个周期为20.1年,离心率为0.78的目视双星。它在2019.1年的近星点被光谱观测到,产生质量(1.10+-0.04和0.98+-0.03 M_sun)和轨道视差,14.90+-0.37 mas。质量、光度和颜色与主序星的演化模型基本一致。组分Aa具有可检测的锂线,而在Ab中不存在。对Ba,Bb是一个单线光谱双星,周期为0.55552天,轨道倾角为~45度,通过模拟旋转加宽的“平底”线轮廓获得。Bb的质量约为0.4 M太阳。恒星B是色球活动的(一个X射线源);它的通量除了偶尔的耀斑外,还受到恒星黑子的轨道周期调制。该系统的年龄可能超过6亿年;它不属于任何已知的移动群。

英文摘要:

HIP 45734 is a quadruple system of 2+2 architecture located at 68 pc from the Sun. The outer 9" system A,B has a period of ~10^4 yr. The pair Aa,Ab is a visual binary with a period of 20.1 years and an eccentricity of 0.78. Its periastron in 2019.1 was observed spectroscopically, yielding masses (1.10+-0.04 and 0.98+-0.03 M_sun) and orbital parallax, 14.90+-0.37 mas. The masses, luminosities, and colors approximately agree with evolutionary models of main sequence stars. The component Aa has a detectable lithium line, whereas in Ab it is absent. The pair Ba,Bb is a single-lined spectroscopic binary with a period of 0.55552 day and an orbital inclination of ~45 deg derived by modeling the rotationally broadened line profile with ``flat bottom''. The mass of Bb is ~0.4 M_sun. The star B is chromospherically active (an x-ray source); its flux is modulated with the orbital period by starspots, in addition to occasional flares. The system is probably older than ~600 Myr; it does not belong to any known moving group.

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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