RS CVn型密近双星CG Cyg和V471 Tau的轨道周期分析
发布时间：2019-04-15 18:07
【摘要】：密近双星的种类有很多，但在众多的密近双星中，RS CVn型密近双星有着独特的物理性质。RS CVn型密近双星是一种色球活动双星，具有较强的磁活动，表现出许多类似太阳的磁活动现象，如：H和CaII的H、K等谱线发射，黑子活动，耀斑，，星风损失等。这些活动直接或间接引起双星系统的轨道周期变化。 本文首先对研究RS CVn型双星的轨道周期变化的方法和引起轨道周期变化的机制进行了简单的阐述，然后详细分析了RS CVn型双星CG Cyg和V471Tau的轨道周期变化。我们得到的主要结果如下： 1.对RS CVn型双星CG Cyg的轨道周期进行了分析。通过对CG Cyg的轨道周期的研究历史进行周密地调研，我们知道，CG Cyg的轨道周期是变化的。首先，我们用MiloneZiebarth1974年提出的一个历元公式对收集的极小时刻数据进行计算，得到O C值，用最小二乘方法拟合O C曲线，得到CG Cyg双星系统的轨道周期变化存在两个调制周期:61.63yr和20.34yr，同时，发现CG Cyg的轨道周期还伴随着一个长期的增加，增加率为dP/dt9.77(2.17)10~(-9) dyr~(-1)；然后又用一个较新的历元公式对数据进行了计算，得到一条新的O C曲线，同样用最小二乘方法对新的O C曲线进行拟合，得到轨道周期的周期性变化的调制周期分别为18.9yr和21.6yr，而其长期的轨道周期增加率为dP/dt2.41(0.17)10~(-8) dyr~(-1)。这两组结果显然不一致。为了验证这些结果，我们又分别对这两个历元公式计算得到的O C用多项式拟合。计算结果表明，拟合基于用MiloneZiebarth在1974年提出的历元公式计算得到的O C曲线获得轨道周期变化的调制周期分别为P(mod1)127.8yr和P(mod)263.9yr；拟合基于用新的历元公式计算得到的O C曲线获得轨道周期变化的调制周期分别为P(mod1)129.2yr和P(mod)264.6yr，并且都伴有一个长期的轨道周期增加：dP/dt2.4810~(-8) dyr~(-1)，由轨道周期的增加率计算得到双星的质量转移率为dM/dt2210~(-8)M111.⊙yr。基于这些计算结果，我们对CGCyg的轨道周期变化原因进行了分析，得到结果为：系统不存在第三天体或是第四天体，调制周期的产生可能是由双星的磁活动引起的，而周期的长期增加可能是由于主星与双星质量中心之间的物质交流造成的。 2.对RS CVn型双星V471Tau的轨道周期进行分析。通过分析，我们得出V471Tau的轨道周期存在一个调制周期为31.1yr的周期性变化，其相应的振幅为PΔ=5~d.59(0d.64)10~(-7)。最后分析总结得出这个周期性的变化可能是由双星系统的磁活动引起的，而不是起因于第三天体的光时轨道效应。
[Abstract]:There are many kinds of close-to-near binary stars, but among many close-near binary stars, RS-CVN-type close-near binary stars have unique physical properties. RS-CVN-type close-near binary star is a kind of chromosphere active binary star with strong magnetic activity. There are many phenomena like solar magnetic activity, such as: h and CaII H, K isospectral emission, sunspot activity, flares, star wind loss and so on. These activities directly or indirectly cause the orbital periodic variation of binary systems. In this paper, the method of studying the orbital periodic variation of the RS CVN binary star and the mechanism of the orbital periodic variation are briefly described. Then, the orbital periodic variation of the RS CVn type binary star CG Cyg and V471Tau is analyzed in detail. The main results we have obtained are as follows: 1. The orbital period of RS CVN type double star CG Cyg is analyzed. Through a thorough investigation of the history of the orbital cycle of CG Cyg, we know that the orbital period of, CG Cyg is variable. First, we use Milone Ziebar's 1974 calendar formula to calculate the collected minimum time data and obtain the OC value. The O-C curve is fitted by the least squares method. It is obtained that there are two modulation periods in the orbit period of the CG Cyg binary system: 61.63yr and 20.34yr. At the same time, it is found that the orbital period of CG Cyg is accompanied by a long-term increase. The increase rate was dP/dt9.77 (2.17) 10 ~ (- 9) dyr~ (- 1); Then, a new O-C curve is obtained by calculating the data with a relatively new epoch formula, and the new O-C curve is also fitted by the least squares method, and the new O-C curve is fitted by the least square method, and the new O-C curve is fitted by the least square method. It is obtained that the modulation period of the periodic variation of the orbital period is 18.9yr and 21.6 yr respectively, and the increasing rate of the long-term orbital period is dP/dt2.41 (0.17) 10 ~ (- 8) dyr~ (- 1). The results of the two groups were clearly inconsistent. In order to verify these results, we also use polynomials to fit the O C calculated by these two epoch formulas respectively. The calculated results show that the modulation periods of the O-C curve obtained by fitting the O-C curve based on the calendar formula proposed by MiloneZiebarth in 1974 are P (mod1) 127.8yr and P (mod) 263.9 yr, respectively. Based on the O-C curve calculated by the new calendar formula, the modulation periods of the orbital periodic variation are P (mod1) 129.2yr and P (mod) 264.6 yr, respectively. DP/dt2.4810~ (- 8) dyr~ (- 1) is accompanied by a long-term increase of orbital period. The mass transfer rate of binary star is dM/dt2210~ (- 8) M11.1 yr. calculated from the increase rate of orbital period. Based on these results, we analyze the causes of the orbital period variation of CGCyg. The results are as follows: there is no third or fourth object in the system, and the generation of modulation period may be caused by the magnetic activity of binary stars. The long-term increase in the cycle may be due to the material exchange between the master star and the mass center of the binary star. 2. The orbital period of RS CVN type double star V471Tau is analyzed. Through the analysis, it is concluded that there is a periodic change in the orbital period of V471Tau with a modulation period of 31.1yr, and the corresponding amplitude is P 螖 = 5~d.59 (0d.64) 10 ~ (- 7). Finally, it is concluded that this periodic change may be caused by the magnetic activity of the binary system, rather than the optical-temporal orbital effect of the third object.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：P153
本文编号：2458361
[Abstract]:There are many kinds of close-to-near binary stars, but among many close-near binary stars, RS-CVN-type close-near binary stars have unique physical properties. RS-CVN-type close-near binary star is a kind of chromosphere active binary star with strong magnetic activity. There are many phenomena like solar magnetic activity, such as: h and CaII H, K isospectral emission, sunspot activity, flares, star wind loss and so on. These activities directly or indirectly cause the orbital periodic variation of binary systems. In this paper, the method of studying the orbital periodic variation of the RS CVN binary star and the mechanism of the orbital periodic variation are briefly described. Then, the orbital periodic variation of the RS CVn type binary star CG Cyg and V471Tau is analyzed in detail. The main results we have obtained are as follows: 1. The orbital period of RS CVN type double star CG Cyg is analyzed. Through a thorough investigation of the history of the orbital cycle of CG Cyg, we know that the orbital period of, CG Cyg is variable. First, we use Milone Ziebar's 1974 calendar formula to calculate the collected minimum time data and obtain the OC value. The O-C curve is fitted by the least squares method. It is obtained that there are two modulation periods in the orbit period of the CG Cyg binary system: 61.63yr and 20.34yr. At the same time, it is found that the orbital period of CG Cyg is accompanied by a long-term increase. The increase rate was dP/dt9.77 (2.17) 10 ~ (- 9) dyr~ (- 1); Then, a new O-C curve is obtained by calculating the data with a relatively new epoch formula, and the new O-C curve is also fitted by the least squares method, and the new O-C curve is fitted by the least square method, and the new O-C curve is fitted by the least square method. It is obtained that the modulation period of the periodic variation of the orbital period is 18.9yr and 21.6 yr respectively, and the increasing rate of the long-term orbital period is dP/dt2.41 (0.17) 10 ~ (- 8) dyr~ (- 1). The results of the two groups were clearly inconsistent. In order to verify these results, we also use polynomials to fit the O C calculated by these two epoch formulas respectively. The calculated results show that the modulation periods of the O-C curve obtained by fitting the O-C curve based on the calendar formula proposed by MiloneZiebarth in 1974 are P (mod1) 127.8yr and P (mod) 263.9 yr, respectively. Based on the O-C curve calculated by the new calendar formula, the modulation periods of the orbital periodic variation are P (mod1) 129.2yr and P (mod) 264.6 yr, respectively. DP/dt2.4810~ (- 8) dyr~ (- 1) is accompanied by a long-term increase of orbital period. The mass transfer rate of binary star is dM/dt2210~ (- 8) M11.1 yr. calculated from the increase rate of orbital period. Based on these results, we analyze the causes of the orbital period variation of CGCyg. The results are as follows: there is no third or fourth object in the system, and the generation of modulation period may be caused by the magnetic activity of binary stars. The long-term increase in the cycle may be due to the material exchange between the master star and the mass center of the binary star. 2. The orbital period of RS CVN type double star V471Tau is analyzed. Through the analysis, it is concluded that there is a periodic change in the orbital period of V471Tau with a modulation period of 31.1yr, and the corresponding amplitude is P 螖 = 5~d.59 (0d.64) 10 ~ (- 7). Finally, it is concluded that this periodic change may be caused by the magnetic activity of the binary system, rather than the optical-temporal orbital effect of the third object.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：P153
【共引文献】
相关硕士学位论文 前1条
1 王晓亮;RS CVn型密近双星SZ Psc和ER Vul的轨道周期分析[D];湘潭大学;2011年
本文编号：2458361
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