KMS of Xinjiang Astronomical Observatory, CAS
| 基于 ASAS-SN 光学时域巡天数据的 W UMa 型食变双星轨道周期变化的分析研究 | |
| Alternative Title | Understanding the orbital period variation of W UMa systems based on time-dominant observations from ASAS-SN sky survey |
鲁利娜
| |
| Subtype | 硕士 |
| Thesis Advisor | 刘进忠 |
| 2020 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 北京 |
| Degree Name | 理学硕士 |
| Degree Discipline | 天体物理 |
| Keyword | 恒星,食双星, W Uma 双星,轨道周期,恒星质量 |
| Abstract | 本文主要讨论了两子星的物质转移，星风，周期性的类太阳磁活动以及第三天体对 W UMa 相接双星轨道周期的影响。我们从 ASAS-SN ( All-Sky Automated Survey for Supernovae ) 观测的 76378 颗源中选择七颗源 ( ASASSN-VJ 000613.43+362657.9，ASASSN-V J000030.35+391106.8，ASASSN-V J000539.51+225251.9， ASASSN-V J000322.83+574452.9， ASASSN-V J000145.82+712002.9，ASASSN-V J084146.74+390531.7 和 ASASSN-V J000322.83+574452.9 ) 作为特征源, 给出了这七颗源的光变曲线。我们更新了源 ASASSN-V J000322.83+574452.9，ASASSN-V J084146.74+390531.7 和 ASASSN-V J000145.82+712002.9的历元公式，并且通过 O-C 方法分析了这三颗源轨道周期变化， ASASSN-V J000322.83+574452.9 的轨道周期长期增大，其轨道周期变化率为 1.656×10-9dyr-1，我们认为该源的轨道周期变化可能是两伴星之间的物质转移造成的；源 ASASSNV J000145.82+712002.9 的轨道周期变化率为 5.064×10-9dyr-1，我们认为第三天体的光时轨道效应造成了该源的轨道周期变化。对于源 ASASSN-V J084146.74+390531.7，其轨道周期变化率为 4.914 × 10-10dyr-1，两伴星间的物质转移率为-3.5082 × 10-9M⊙yr-1，表明两伴星间的物质转移造成了该源的轨道周期变化。W UMa 相接双星的质量参数在研究恒星动力学演化过程和研道周期变化物理机制中扮演着举足轻重的角色。依据前人已有的研究基础，本文归纳总结出两种可以用来确定 W UMa 质量的方法: 等体积半径方法 (a dependent calculation from the W-D code：简称 DCWD ) 和洛希几何方法 ( the dependent calculation from the effective radius of the Roche lobe：简称 DCRL )。 (1) 等体积半径方法: 为了研究等体积半径方法的可信性，我们收集了 65 颗具有可靠测光数据与分光 数据的 W UMa 相接双星，用等体积半径方法重新计算了这些源的质量参数，并且比对了文献值。我们用 t 检验，验证了该方法计算 W UMa 相接双星的质量参数的可靠性，并且我们发现对于 W 次型和 A 次型相接双星，用该方法计算的值与文献中该给定值的偏离度为 0.1159 和 0.1356。 (2) 洛希几何方法：洛希几何方法是结合 PARSEC 恒星演化程序与洛希模型推导的计算 W UMa 相接双星质量的一种的方法。为了验证该方法的可靠性，我们也用该方法计算了 65 颗源的 质量参数。对于 W 次型和 A 次型的源我们发现用该方法计算的质量值与文献中给定的质量值的平均偏离度为 0.1143 和 0.1393。我们也根据轨道周期，有效温度以及质量比对该方法进行了分析，发现用该方法更适合于确定低温的短周期的相接双星的质量。 |
| Other Abstract | In this paper， we studied the physical processes of period variation in contact binary systems. The period variation could be cased by the mass and energy exchange between the components , stellar wind, magnetic activity and the lighttravel time effect by a third body. The seven of 76378 W UMa binaries observed by ASAS-SN (All-Sky Automated Survey for Supernovae) are selected as samples. We displayed the V-band light curve of these seven targets. The linear ephemeris of targets ASASSN-V J000322.83+574452.9, ASASSN-V J084146.74+390531.7 and ASASSN-V J000145.82+712002.9 are updated. The investigations of orbital period for these three systems indicate that the periods are variable. The orbital periods of the three targets were discovered to have secularly increasing with rates of 1.656 × 10-9dyr-1，5.064 × 10-9dyr-1 and 4.914 × 10-10dyr-1，respectively.The masses of W UMa binaries play an important role in investigating the stellar dynamic evolution and physical mechanism of period variation. In this paper, based on PAdova and TRieste Stellar Evolution Code (PARSEC), we propose two methods for estimating masses of W UMa stars: a dependent calculation from the W-D code (DCWD) and the dependent calculation from the effective radius of the Roche lobe (DCRL). (1)In this work, in order to verify the reliability of the DCWD method, we collected 65 W UMa binaries with reliable photometric data and spectroscopic data, and calculated the masses for these targets by the DCWD method. we compare the difference between the masses value calculated from literature. using a t-test， We find that the method is reliable for determine the masses of W UMa stars.We find that the the average fractional difference of the residuals for W-subtype and A-subtype approximately amount to 0.1976 and 0.2094. (2)The DCRL method combines the PARSEC and the Roche geometric model. To verify the validity of this method, we calculated the mass for these 65 targets by the DCRL method. We find that the average fractional difference of the residuals for W-subtype and A-subtype approximately amount to 0.1159 and 0.1356 . Meanwhile, we also perform detailed analyses in accordance with the orbital period, the effective temperatures and the mass ratio. We find that the method is more applicable to determine masses for W UMa systems with low effective temperature and short period. |
| Pages | 66 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.xao.ac.cn/handle/45760611-7/4139 |
| Collection | 研究生学位论文 |
| Affiliation | 中国科学院新疆天文台 |
| First Author Affilication | Xinjiang Astronomical Observatory, Chinese Academy of Sciences |
| Recommended Citation GB/T 7714 | 鲁利娜. 基于 ASAS-SN 光学时域巡天数据的 W UMa 型食变双星轨道周期变化的分析研究[D]. 北京. 中国科学院大学,2020. |
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| 鲁利娜.pdf（13851KB） | 学位论文 | 暂不开放 | CC BY-NC-SA | Application Full Text | ||
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