RS CVn型密近雙星CG Cyg和V471 Tau的軌道周期分析
發(fā)布時間：2019-04-15 18:07
【摘要】：密近雙星的種類有很多，但在眾多的密近雙星中，RS CVn型密近雙星有著獨特的物理性質(zhì)。RS CVn型密近雙星是一種色球活動雙星，具有較強的磁活動，表現(xiàn)出許多類似太陽的磁活動現(xiàn)象，如：H和CaII的H、K等譜線發(fā)射，黑子活動，耀斑，，星風損失等。這些活動直接或間接引起雙星系統(tǒng)的軌道周期變化。 本文首先對研究RS CVn型雙星的軌道周期變化的方法和引起軌道周期變化的機制進行了簡單的闡述，然后詳細分析了RS CVn型雙星CG Cyg和V471Tau的軌道周期變化。我們得到的主要結(jié)果如下： 1.對RS CVn型雙星CG Cyg的軌道周期進行了分析。通過對CG Cyg的軌道周期的研究歷史進行周密地調(diào)研，我們知道，CG Cyg的軌道周期是變化的。首先，我們用MiloneZiebarth1974年提出的一個歷元公式對收集的極小時刻數(shù)據(jù)進行計算，得到O C值，用最小二乘方法擬合O C曲線，得到CG Cyg雙星系統(tǒng)的軌道周期變化存在兩個調(diào)制周期:61.63yr和20.34yr，同時，發(fā)現(xiàn)CG Cyg的軌道周期還伴隨著一個長期的增加，增加率為dP/dt9.77(2.17)10~(-9) dyr~(-1)；然后又用一個較新的歷元公式對數(shù)據(jù)進行了計算，得到一條新的O C曲線，同樣用最小二乘方法對新的O C曲線進行擬合，得到軌道周期的周期性變化的調(diào)制周期分別為18.9yr和21.6yr，而其長期的軌道周期增加率為dP/dt2.41(0.17)10~(-8) dyr~(-1)。這兩組結(jié)果顯然不一致。為了驗證這些結(jié)果，我們又分別對這兩個歷元公式計算得到的O C用多項式擬合。計算結(jié)果表明，擬合基于用MiloneZiebarth在1974年提出的歷元公式計算得到的O C曲線獲得軌道周期變化的調(diào)制周期分別為P(mod1)127.8yr和P(mod)263.9yr；擬合基于用新的歷元公式計算得到的O C曲線獲得軌道周期變化的調(diào)制周期分別為P(mod1)129.2yr和P(mod)264.6yr，并且都伴有一個長期的軌道周期增加：dP/dt2.4810~(-8) dyr~(-1)，由軌道周期的增加率計算得到雙星的質(zhì)量轉(zhuǎn)移率為dM/dt2210~(-8)M111.⊙yr�；谶@些計算結(jié)果，我們對CGCyg的軌道周期變化原因進行了分析，得到結(jié)果為：系統(tǒng)不存在第三天體或是第四天體，調(diào)制周期的產(chǎn)生可能是由雙星的磁活動引起的，而周期的長期增加可能是由于主星與雙星質(zhì)量中心之間的物質(zhì)交流造成的。 2.對RS CVn型雙星V471Tau的軌道周期進行分析。通過分析，我們得出V471Tau的軌道周期存在一個調(diào)制周期為31.1yr的周期性變化，其相應(yīng)的振幅為PΔ=5~d.59(0d.64)10~(-7)。最后分析總結(jié)得出這個周期性的變化可能是由雙星系統(tǒng)的磁活動引起的，而不是起因于第三天體的光時軌道效應(yīng)。
[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.
【學(xué)位授予單位】：湘潭大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2012
【分類號】：P153
本文編號：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.
【學(xué)位授予單位】：湘潭大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2012
【分類號】：P153
【共引文獻】
相關(guān)碩士學(xué)位論文 前1條
1 王曉亮;RS CVn型密近雙星SZ Psc和ER Vul的軌道周期分析[D];湘潭大學(xué);2011年
本文編號：2458361
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