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Eclipsing binary XZ CMi in a hierarchical quadruple system

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Research in Astronomy and Astrophysics 2020年第8期20卷 307-315页

作者： Zhi-Hua Wang li-ying zhu Yunnan Observatories Chinese Academy of SciencesKunming 650216China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China Center for Astronomical Mega-Science Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

The new complete BV Rc Ic light curves and spectra of the short-period eclipsing binary XZ CMi are *** results from the combined analysis based on the photometric and spectroscopic data show that XZ CMi is a near contact binary with the secondary component filling its critical Roche lobe while the primary filling 91%of its Roche *** investigation of the O-C diagram reveals that its orbital period is continuously increasing,which is consistent with the derived configuration and caused by the mass transfer from the less massive star to the more massive *** addition,an obvious periodic modulation with the amplitude of0.0187(±0.0016)d and a high eccentric of 0.86(±0.04)is detected,which could be the results of the light time effect as a third star with the mass no less than 0.42(±0.09)M⊙orbiting around the central eclipsing binary once every 95.7(±2.1)***,we found a visual companion star at 2.4′′east by south of this system at a much greater distance by direct *** large third light contribution found from the light curve analysis could be well explained by the existence of the third star and the fourth visual *** similar parallax and proper motion imply that the components of this hierarchical quadruple system might be bounded by *** observations for two visual components were carried out by the LAMOST and 2.16 m telescopes,*** different values of[Fe/H]suggest that they were not born from the same ***,XZ CMi system is an interesting and important target to study the formation of the multiple stars.

关键词： binaries:close binaries:eclipsing stars:individual(XZ CMi)

A low-mass-ratio and deep contact binary as the progenitor of the merger V1309 Sco

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Research in Astronomy and Astrophysics 2016年第4期16卷 129-132页

作者： li-ying zhu Er-Gang Zhao Xiao Zhou Yunnan Observatories Chinese Academy of SciencesKunming 650011China Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650011China University of the Chinese Academy of Sciences Beijing 100049China

Nova Sco 2008 （=V1309 Sco） is an example of a V838 Mon type eruption rather than a typical classical nova. This enigmatic object was recently shown to have resulted from the merger of two stars in a contact binary. It is the first stellar merger that was identified to be undergoing a common envelope transient. To understand the properties of its binary progenitor, the pre-outburst light curves were analyzed by using the W-D method. The photometric solution of the 2002 light curve shows that it is a deep contact binary （f = 89.5（~40.5）%） with a mass ratio of 0.094. The asymmetry of the light curve is explained by the presence of a dark spot on the more massive component. The extremely high fill-out factor suggests that the merging of the contact binary is driven by dynamical mass loss from the outer Lagrange point. However, the analysis of the 2004 light curve indicates that no solutions were obtained even at an extremely low mass ratio of q = 0.03. This suggests that the common convective envelope of the binary system disappeared and the secondary component spiraled into the envelope of the primary in 2004. Finally, the ejection of the envelope of the primary produced the outburst.

关键词： stars: binaries: close -- stars: binaries: eclipsing -- stars: individuals (V1309 Sco) -- stars:evolution -- stars: mass-loss

Period investigation of Algol systems TZ Eri and TU Her

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Research in Astronomy and Astrophysics 2019年第8期19卷 11-18页

作者： Zhi-Hua Wang li-ying zhu lin-Jia li Xiao-Man Tian Yunnan Observatories Chinese Academy of SciencesKunming650216China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming650216China Center for Astronomical Mega-Science Chinese Academy of SciencesBeijing100101China University of Chinese Academy of Sciences Beijing100049China

TZ Eri and TU Her are both classic Algol-type systems(Algols). By observing and collecting times of minimum light, we constructed the O-C curves for the two systems. The long-time upward and downward parabolas shown in these diagrams are considered to be the result of the combination of mass transfer and angular momentum loss. The secular orbital period change rates are d P/dt = 4.74(±0.12) ×10-7 d yr-1 and d P/dt =-2.33(±0.01) × 10-6 d yr-1, respectively. There are also cyclic variations in their O-C curves which might be caused by the light-travel time effect(LTTE). A circumbinary star may exist in the TZ Eri system with a mass of at least 1.34 M⊙, while there are possibly two celestial bodies that almost follow a 2 : 1 resonance orbit around the TU Her binary pair. Their masses are at least 2.43 M⊙and 1.27 M⊙.

关键词： stars:binaries:close stars:binaries:eclipsing stars:individual (TZ Eri, TU Her)

Effects of PAHs on Biotransformation Enzymatic Activities in Fish

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Chemical Research in Chinese Universities 2011年第3期27卷 413-416页

作者： LU Guang-hua CHEN Wei li ying zhu Zhi Key Laboratory of Integrated Regulation and Resources Development of Shallow Lakes Ministry of Education College of Environment Hohai University Nanjing 210098 P. R. China

Biotransformation and detoxification responses to the exposure to five polycyclic aromatic hydrocarbons were investigated in crucian（Carassius auratus）. Juvenile crucian were treated with a single intraperitoneal injection of each compound at dosages of 0.1, 1.0, 2.0, 5.0 and 8.0（or 10.0） mg/kg and sacrificed 15 d later to determine 7-ethoxyresorufin-O-deethylase（EROD） and glutathione S-transferases（GST） activities in gill S9 fractions. EROD activity is significantly increased by benzo（b）fluoranthene and indeno（1,2,3-cd）pyrene at all the doses. High dosages of PAHs induced GST activity and the inducing ability of them increased in the following order： fluorene fluorantheneindeno（1,2,3-cd）pyrenebenzo（g,h,i）perylenebenzo（b）fluoranthene. In all the cases, dose dependence appeared to exist. The gill EROD and GST in Carassius auratus are useful biomarkers to estimate sub-acute toxicity of both polycyclic aromatic hydrocarbons（PAHs） and PAHs-like compounds.

关键词： Polycyclic aromatic hydrocarbon Gill 7-Ethoxyresorufin-O-deethylase activity Glutathione S-transferases activity

Identification of temperature anomaly RR Lyrae stars in LAMOST survey,misclassification and binarities

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Research in Astronomy and Astrophysics 2020年第6期20卷 239-252页

作者： lin-Jia li Sheng-Bang Qian Jia Zhang Jia-Jia He li-ying zhu Yunnan Observatories Chinese Academy of SciencesKunming 650216China Key laboratory of the structure and evolution of celestial objects Chinese Academy of SciencesKunming 650216China Center for Astronomical Mega-Science Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

RR Lyrae stars,a well-known type of pulsating variable stars,have been known about for more than a century.A large amount of photometric data on RR Lyrae stars has been accumulated by space-and ground-based sky surveys,but the spectral data are relatively ***,the LAMOST sky survey project provides an opportunity to view them from the point of view of *** collect the atmospheric parameters of 1685 RR Lyrae stars provided by the LAMOST catalog,and carry out research by using the reliable *** find that there is a clear correlation between their Teff and pulsation periods,which is consistent with the pulsation and evolution theories of RR Lyrae *** addition,we focus on those RR Lyrae stars with abnormal *** analyzing the data from several photometric surveys,we find that some of these temperature anomalies are misclassified variable stars(e.g.,eclipsing binaries,pulsating stars on main sequence),and some are RR Lyrae binary *** the latter,the temperatures of potential companions should be lower and their luminosities should not be neglected(e.g.,red giant stars).We obtain that the ratio of temperature anomaly stars to all the sample stars is 4%,which means that the impact on the further analysis(e.g.,kinematics analysis)is *** also present the catalogs of spectral anomaly RR Lyrae stars.

关键词： techniques spectroscopic-techniques photometric-stars fundamental parameters-stars variables RR Lyrae

Long-term photometric behavior of the eclipsing Z Cam-type dwarf nova AY Psc

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Research in Astronomy and Astrophysics 2017年第6期17卷 67-76页

作者： Zhong-Tao Han Sheng-Bang Qian Irina Voloshina li-ying zhu Yunnan Observatories Chinese Academy of Sciences Kunming 650216 China Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming 650216 China University of Chinese Academy of Sciences Beijing 100049 China Sternberg Astronomical Institute Moscow State University Universitetskij prospect 13 Moscow 119992 Russia

New eclipse timings of the Z Cam-type dwarf nova AY Psc were measured and the orbital ephemeris was revised. In addition, based on long-term AAVSO data, the outburst behaviors were also explored. Our analysis suggests that normal outbursts are quasi-periodic, with an amplitude of 2.5（4-0.1） mag and a period of - 18.3（4-0.7） d. The amplitude vs. recurrence-time relation ofAY Psc is discussed, and we conclude that this relation may represent general properties of dwarf nova outbursts. The observed standstill ends with an outburst, which is inconsistent with the general picture of Z Cam- type stars. This unusual behavior was considered to be related to mass-transfer outbursts. Moreover, the average luminosity Is brighter during standstills than during outburst cycles. The changes in brightness mark variations in M2 due to the fact that the disk of AY Psc is nearly steady state.M2 value was limited to the range from 6.35 × 10-9 to 1.18 × 10-8 M yr-1. More detailed examination shows that there are a few small outbursts present during standstills. These events with amplitudes of - 0.5 - 0.9 mag are very similar to the stunted outbursts reported in some nova-like cataclysmic variables. We discussed several possible mechanisms and suggested that the most reasonable mechanism for these stunted outbursts is a changing mass-transfer rate.

关键词： binaries close - stars cataclysmic variables - stars individual (AY Psc)

Photometric investigation of the eclipsing binary TX Herculis observed by LUT

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Research in Astronomy and Astrophysics 2019年第7期19卷 47-52页

作者： li-ying zhu Xiao-Man Tian Xiao Zhou lin-Jia li Zhi-Hua Wang Yunnan Observatories Chinese Academy of SciencesKunming 650216China Center for Astronomical Mega-Science Chinese Academy of SciencesBeijing 100101China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China University of the Chinese Academy of Sciences Beijing 100049China

The lander of China’s Chang’E-3 spacecraft is equipped with a 15-cm telescope that is very useful for monitoring celestial objects in the ultraviolet(UV) band(245–340 nm).The Lunar-based Ultraviolet Telescope(LUT) is the first long-term lunar-based astronomical observatory,that can make uninterrupted observations of a target from the *** we present the continuous complete UV light curve of the eclipsing binary TX Herculis(TX Her).The analysis of the light curve suggests that TX Her is a detached *** dip in the light curve was explained by the emergence of a stellar dark spot on the less massive F0 type *** cyclic change of arrival eclipse times for the system reveals that it contains an additional stellar companion with a minimal mass of 0.35 M⊙ and a period of 48.92 yr,which is supported by the detected light contribution of the third body from light curve *** third body may play an important role in the formation of the present short-period system TX Her.

关键词： stars:binaries:close stars:binaries:eclipsing stars:individuals (TX Herculis) stars:multiple system stars:activity

Lunar-based Ultraviolet Telescope study of the well-known Algol-type binary TW Dra

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Research in Astronomy and Astrophysics 2016年第6期16卷 93-98页

作者： Wen-Ping liao Sheng-Bang Qian Miloslav Zejdat li-ying zhu lin-Jia li Yunnan Observatories Chinese Academy of Sciences Kunming 650216 China Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming 650216China University of Chinese Academy of Sciences Beijing 100049 China Department of Theoretical Physics and Astrophysics Masaryk University Kotlarska 2 CZ-611 37 Brno Czech Republic

By using the Lunar-based Ultraviolet Telescope （LUT） from 2014 December 2 to December 4, the first near-UV light curve of the well-known Algol-type binary TW Dra is reported, which is analyzed with the 2013 version of the W-D code. Our solutions confirmed that TW Dra is a semi-detached binary system where the secondary component fills its Roche lobe. The mass ratio and a high inclination are obtained （q = 0.47, i = 86.68°）. Based on 589 available data spanning more than one century, the complex period changes are studied. Secular increase and three cyclical changes are found in the corresponding orbital period analysis. The secular increase changes reveal mass transfer from the secondary component to the primary one at a rate of 6.8 × 10-7 M yr-1. One large cyclical change of 116.04 yr may be caused by disturbance of visual component ADS 9706B orbiting TW Dra （ADS 9706A）, while the other two cyclical changes with shorter periods of 22.47 and 37.27 yr can be explained as the result of two circumbinary companions that are orbiting around TW Dra, where the two companions are in simple 3 ： 5 orbit-rotation resonances. TW Dra itself is a basic binary in a possible sextuple system with the configuration （1 ＋ 1）＋（1 ＋ 1）＋（1 ＋ 1）, which further suggests that multiplicity may be a fairly common phenomenon in close binary systems.

关键词： stars: binaries: close -- stars: binaries: eclipsing -- stars: individual (TW Draco)

High amplitude δ Scuti star BO Lyn with evidence of a late A-type companion in an elliptical orbit

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Research in Astronomy and Astrophysics 2018年第1期18卷 119-126页

作者： lin-Jia li Sheng-Bang Qian Jia Zhang li-ying zhu Wen-Ping liao Yunnan Observatories Chinese Academy of Sciences Kunming 650216 China Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming 650216 China Center for Astronomical Mega-Science Chinese Academy of Sciences Beijing 100012 China University of Chinese Academy of Sciences Beijing 100049 China

We present 145 times of light maximum for high amplitude δ Scuti star BO Lyn based on several sky surveys（CRTS,DASCH,NSVS,OMC and Super WASP）and our photometric *** with the data in literature,a total of 179 times of light maximum are used to analyze the O-C diagram of BO *** find that it can be described by an upward parabolic component and a periodic variation with a period of 34.5±0.1 *** latter could be caused by the light travel time effect as a result of an additional companion orbiting in a highly elliptical orbit（e=0.64±0.03）.Our study indicates that the companion’s luminosity cannot be ignored,and it should be a late A-type main-sequence *** long-term period change of BO Lyn is also detected,and its value,1.52±0.26×10^（-3）d Myr^（-1）,is consistent with evolutionary *** suggest that more spectroscopic and photometric observations are needed in the future to confirm the nature of the BO Lyn system.

关键词： techniques:photometric stars:variables:δ Scuti stars:individual(BO Lyn)