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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

New multi-color photometric investigations of solar-like contact binary V680 Per

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Research in Astronomy and Astrophysics 2020年第4期20卷 49-56页

作者： Jing-Jing Wang jia-jia he Song-Qing Zhao China University of Petroleum–Beijing at Karamay Karamay 834000China Yunnan Observatories Chinese Academy of SciencesKunming 650216China Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China

High-precision CCD photometric observations of the contact binary V680 Per were obtained *** symmetric multi-color light curves were analyzed by using the Wilson–Devinney(2013)*** photometric solutions suggest that V680 Per is an A-type W UMa contact binary with the mass ratio of q=0.693 and a fill-out factor of f=18.84%with a small temperature difference of 101 *** on all minimum times,the O-C curve was analyzed for the first time in this study.A cyclic oscillation(A3=0.00093 d,T3=4.92 yr)superimposed on a secular decrease(d P/dt=-8.16×10-8 d yr-1)was *** continuous decrease in period is possibly a result of mass transfer from the more massive component to the less massive one,or angular momentum loss due to a magnetic stellar *** of this secular decrease,it is predicted that the degree of contact will become higher,and V680 Per will evolve into a deeper overcontact binary.

关键词： binaries:eclipsing stars:solar-type stars:individual(V680 Per)

Revision of the photometric parameters of BS Cassiopeiae

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Research in Astronomy and Astrophysics 2010年第6期10卷 569-576页

作者： jia-jia he Sheng-Bang Qian Miloslav Zejda Zdenek Mikulasek National Astronomical Observatories / Yunnan Observatory Chinese Academy of Sciences Kunming 650011 China Graduate University of the Chinese Academy of Sciences Beijing 100049 China Key Laboratory for the Structure and Evolution of Celestial Objects National Astronomical Observatories/Yunnan Observatory Chinese Academy of Sciences Kunming 650011 China Institute of Theoretical Physics and Astrophysics Masaryk University Kotlarska 2 611 37 Brno Czech Republic Observatory and Planetarium of J. Palisa VSB- Technical University Ostrava Czech Republic

Seven charge-coupled device （CCD） photometric times of light minimum of the overcontact binary BS Cas which were obtained from 2007 August to November and one CCD light curve in the R band which was observed on 2007 September 24 and October 15, are presented. It is found that the light curve ofBS Cas has characteristics like a typical EW-type light variation. The light curve obtained by us is symmetric and shows total eclipses, which is very useful for determining photometric parameters with high precision. Photometric solutions were derived by using the 2003 version of the Wilson-Devinney code. It shows that BS Cas is a W-subtype overcontact binary （f = 27.5% ± 0.4%） with a mass ratio of q = 2.7188± 0.0040. The temperature difference between the two components is 190 K. Analysis of the 042 curve suggests that the period of AE Phe shows a long-term continuous decrease at a rate of dP/dt = - 2.45 × 10^-7 d yr^- 1 The long-time period decrease can be explained by mass transfer from the primary to the secondary.

关键词： stars binaries close -- stars binaries eclipsing -- stars individual BS Cas

Physical properties of γ Doradus pulsating stars and their relationship with long-period δ Scuti variables

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Research in Astronomy and Astrophysics 2019年第1期19卷 1-20页

作者： Sheng-Bang Qian Lin-jia Li jia-jia he jia Zhang Li-Ying Zhu Zhong-Tao Han Yunnan Observatories Chinese Academy of Sciences Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Center for Astronomical Mega-Science Chinese Academy of Sciences University of Chinese Academy of Sciences

We present LAMOST data on 168 γ Doradus(γ Dor) pulsating stars including stellar atmospheric parameters of 137 variables and spectral types for all of the samples. The distributions of period(P), temperature(T), gravitational acceleration(log(g)) and metallicity [Fe/H] are shown. It is found that most γ Dor variables are main-sequence stars with early F spectral types and temperatures from 6880 K to7280 K. They are slightly more metal poor than the Sun with a metallicity range from-0.4 to 0. On the H-R and log g-T diagrams, both the γ Dor and δ Scuti(δ Sct) stars occupy in the same region and some are beyond the borders predicted by current stellar pulsation theories. It is discovered that the physical properties of γ Dor stars are similar to those of long-period δ Sct(P > 0.3 d) stars. The stellar atmospheric parameters are all correlated with the pulsation period for short-period δ Sct variables(P here are no such relations for γ Dor or long-period δ Sct stars. These results reveal that γ Dor and long-period δ Sct are the same group of pulsating stars and they are different from short-period δ Sct variables. Meanwhile, 33γ Dor stars are identified as candidates of binary or multiple systems.

关键词： stars:fundamental parameters stars:oscillations stars:binaries:spectroscopic stars:variables:other

Contact binaries at different evolutionary stages

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Research in Astronomy and Astrophysics 2020年第10期20卷 229-248页

作者： Sheng-Bang Qian Li-Ying Zhu Liang Liu Xu-Dong Zhang Xiang-Dong Shi jia-jia he jia Zhang Yunnan Observatories Chinese Academy of SciencesKunming 650216China School of Physics and Astronomy Yunnan UniversityKunming 650091China 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

Contact binaries consist of two strongly interacting component stars where they are filling their critical Roche lobes and sharing a common *** of them are main-sequence stars,but some of them are post main-sequence *** are good astrophysical laboratories for studying several problems such as the merging of binary stars,evolution of the common envelope,the origin of luminous red nova outbursts and the formation of rapidly rotating single stars with possible planetary systems.A large number of contact binary candidates were detected by several photometric surveys around the world and many of them were observed by the LAMOST spectroscopic *** on follow-up observations,the evolutionary states and geometrical structures of some systems were understood *** this review,we will introduce and catalog new stellar atmospheric parameters(i.e.,the effective temperature(Teff),the gravitational acceleration(log(g)),metallicity([Fe/H])and radial velocity(Vr))for 9149 EW-type contact binaries that were obtained based on low-and medium-resolution spectroscopic surveys of *** we will focus on several groups of contact binary stars,i.e.,marginal contact binary systems,deep and low-mass ratio contact binary stars,binary systems below the short-period limit of contact binaries and evolved contact *** contact binaries are at the beginning of the contact stage,while deep and low-mass ratio contact binary stars are at the final evolutionary stage of tidally locked *** statistical relations including the period-temperature relation are determined well by applying LAMOST data and their formation and evolutionary states are *** period-color relation of M-type binaries reveals that there are contact binaries below the short-period *** for and investigating contact binaries near and below this limit will help us to understand the formation of contact binary systems and a new prediction for the short-period l

关键词： binaries:eclipsing stars:late-type stars:low-mass stars:formation stars:evolution

Physical properties and catalog of EW-type eclipsing binaries observed byLAMOST

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Research in Astronomy and Astrophysics 2017年第8期17卷 109-122页

作者： Sheng-Bang Qian jia-jia he jia Zhang Li-Ying Zhu Xiang-Dong Shi Er-Gang Zhao Xiao Zhou Yunnan Observatories Chinese Academy of Sciences Kunming 650011 China Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming650216 China Center for Astronomical Mega-Science Chinese Academy of Sciences Beijing 100012 China University of the Chinese Academy of Sciences Beijing 100049 China

EW-type eclipsing binaries(hereafter called EWs)are strong interacting systems in which both component stars usually fill their critical Roche lobes and share a common *** EWs were discovered by several deep photometric surveys and there were about 40 785 EW-type binary systems listed in the international variable star index(VSX)by 2017 March 13.7938 of them were observed with LAMOST by 2016 November 30 and their spectral types were *** atmospheric parameters of 5363 EW-type binary stars were determined based on good spectroscopic *** the paper,those EWs are cataloged and their properties are *** distributions of orbital period(P),effective temperature(T),gravitational acceleration(log(g)),metallicity([Fe/H])and radial velocity(RV)are presented for these observed EW-type *** is shown that about 80.6% of sample stars have metallicity below zero,indicating that EW-type systems are old stellar *** is in agreement with the conclusion that EW binaries are formed from moderately close binaries through angular momentum loss via magnetic braking that takes a few hundred million to a few billion *** unusually high metallicities of a few percent of EWs may be caused by contamination of material from the evolution of unseen neutron stars or black holes in the *** correlations between orbital period and effective temperature,gravitational acceleration and metallicity are presented and their scatters are mainly caused by(i)the presence of third bodies and(ii)sometimes wrongly determined *** is shown that some EWs contain evolved component stars and the physical properties of EWs mainly depend on their orbital *** is found that extremely short-period EWs may be older than their long-period cousins because they have lower *** reveals that they have a longer timescale of pre-contact evolution and their formation and evolution are mainly driven by angular momentum loss vi

关键词： stars binaries close—stars binaries spectroscopic—stars binaries eclipsing—stars evolution

New photometric investigation of the low-mass-ratio contact binary star V1853 Orionis

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Research in Astronomy and Astrophysics 2019年第4期19卷 77-88页

作者： jia-jia he Sheng-Bang Qian Boonrucksar Soonthornthum Amornrat Aungwerojwit Niang-Ping Liu Thawicharat Sarotsakulchai Yunnan Observatories Chinese Academy of Sciences Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Center for Astronomical Mega-Science Chinese Academy of Sciences University of Chinese Academy of Sciences National Astronomical Research Institute of Thailand 191 Siriphanich Bldg.2nd Fl.Huay Kaew Rd.Suthep DistrictMuang Department of Physics Faculty of Science Naresuan University

Four-color charge-coupled device(CCD) light curves in the B, V, Rc and I c bands of the totaleclipsing binary system V1853 Orionis(V1853 Ori) are presented. By comparing our light curves with those published by previous investigators, it is determined that the O'Connell effect on the light curves has disappeared. By analyzing those multi-color light curves with the Wilson-Devinney code(W-D code),it is discovered that V1853 Ori is an A-type intermediate-contact binary with a degree of contact factor of f = 33.3%(3.7%) and a mass ratio of q = 0.1896(0.0013). Combining our 10 newly determined times of light minima together with others published in the literature, the period changes of the system are investigated. We found that the general trend of the observed minus calculated(O-C) curve shows a downward parabolic variation that corresponds to a long-term decrease in the orbital period with a rate of d P/dt =-1.96(0.46)×10^(-7) d yr^(-1). The long-term period decrease could be explained by mass transfer from the more-massive component to the less-massive one. By combining our photometric solutions with data from Gaia DR_2, absolute parameters were derived as M_1 = 1.20 M⊙, M_2 = 0.23 M⊙, R_1 = 1.36 R⊙and R_2 = 0.66 R⊙. The long-term period decrease and intermediate-contact configuration suggest that V1853 Ori will evolve into a high fill-out overcontact binary.

关键词： stars: binaries:close stars:binaries:eclipsing stars:individual(V1853 Ori)

Photometric investigation of the K-type extremely shallow contact binary V1799 Orion

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Research in Astronomy and Astrophysics 2014年第9期14卷 1157-1165页

作者： Nian-Ping Liu Sheng-Bang Qian Wen-Ping Liao jia-jia he Er-Gang Zhao Liang Liu Yunnan Observatories Chinese Academy of Sciences Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences University of Chinese Academy of Sciences

New multi-color light curves of the very short period K-type eclipsing binary V1799 Ori were obtained and analyzed with the Wilson-Devinney code. The photometric solutions reveal that the system is a W-type shallow-contact binary with a mass ratio of q = 1.335（4-0.005） and a degree of contact of about f = 3.5（-4-1.1）%. In general, the results are in good agreement with what is reported by Samec. Dramatic manifestations of the O＇Connell effect that appear in the light curves can be explained well by employing starspots on the binary surface, which confirms that the system is active at present. Several new times of light minimum were obtained. All the avail- able times of light minimum were collected, along with the recalculated and newly obtained values. Applying a least-squares method to the constructed O - C diagram, a new ephemeris is derived for V1799 Ori. The orbital period is found to show a continuous weak increase at a rate of 1.8（±0.6） × 10^-8 d yr^-1. The extremely shallow contact, together with the period increase, suggests that the binary may be at a critical stage predicted by thermal relaxation oscillation theory.

关键词： binaries: close -- binaries: eclipsing -- stars: individual (V1799 Off)

High expression of protein phosphatase 2 regulatory subunit B''alpha predicts poor outcome in hepatocellular carcinoma patients after liver transplantation

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World Journal of Gastrointestinal Oncology 2021年第7期13卷 716-731页

作者： jia-jia he Lei Shang Qun-Wei Yu Ning jiao Shuang Qiu Wei-Xiong Zhu Dong-Feng Wu Yun-Er Tian Qing Zhang Clinical College of General Hospital of Chinese People's Armed Police Force Anhui Medical UniversityHefei 230032AnhuiChina Department of Organ Transplantation The Third Medical Center of Chinese PLA General HospitalBeijing 100039China Department of health Statistics Fourth Military Medical UniversityXi'an 710032Shanxi ProvinceChina Department of Ophthalmology The Third Medical Center of Chinese PLA General HospitalBeijing 100039China

BACKGROUND Protein phosphatase 2 regulatory subunit B''alpha(PPP2R3A)gene has been reported in other tumors,but the influence of PPP2R3A gene expression on the occurrence,development,and prognosis of hepatocellular carcinoma(HCC)remains *** To investigate whether the PPP2R3A gene could be used to predict tumor recurrence and survival of HCC patients after liver transplantation(LT).METHODS Diseased liver tissues of HCC patients after LT were collected as well as their clinical data and follow-up *** immunohistochemical method was used to detect the expression of PPP2R3A protein in the tissues of 108 patients with primary liver ***χ2 test was used to analyze the relationship between PPP2R3A protein expression levels and the clinicopathological features of *** Kaplan-Meier method was used to analyze overall postoperative *** COX proportional hazard model was used to analyze adverse prognostic *** Immunohistochemistry showed that the PPP2R3A protein was mainly expressed in the cytoplasm of HCC *** to corresponding peritumoral tissues,expression was higher in HCC tissues(P≤0.001).Correlation analysis showed that high PPP2R3A expression was correlated with preoperative serum alphafetoprotein(AFP)levels(P=0.003),tumor-node-metastasis-t stage(P≤0.001),and envelope invasion(P=0.001).Univariate analysis showed that overall survival(P≤0.001)and recurrence-free survival(P=0.025)of patients with high PPP2R3A expression(≥4 points)were poor compared to those with low expression(he overall survival rates or recurrence-free survival rates at 1,2,and 3 years with high PPP2R3A expression were 73%,38%,and 23%or 31%,23%,and 23%,*** analysis showed that high PPP2R3A expression(hazard ratio=2.900,95%confidence interval:1.411–5.960,P=0.004)was an independent survival risk factor of HCC patients after LT,and it was also an independent predictor of postoperative tumor *** study als

关键词： Protein phosphatase 2 regulatory subunit B''α hepatocellular carcinoma Liver transplantation Prognosis Alpha-fetoprotein