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Digitization of astronomical Photographic Plates of china and Astrometric Measurement of Single-exposure Plates

Research in Astronomy and Astrophysics 2024年第5期24卷 103-116页

作者：商正君于涌王亮亮杨美婷杨静沈世银刘敏徐权峰崔辰州樊东卫唐正宏赵建海 Shanghai astronomical observatory Chinese Academy of SciencesShanghai 200030China University of chinese academy of sciences Beijing 100049China Key Lab for Astrophysics Shanghai200234China National astronomical observatories Chinese Academy of SciencesBeijing 100101China National astronomical Data Center Chinese Academy of SciencesBeijing 100101China

From the mid-19th century to the end of the 2.th century, photographic plates served as the primary detectors for astronomical observations. astronomical photographic observations in{2. began in 1901, and over a century, a total of approximately 30,000 astronomical photographic plates were captured. These historical plates play an irreplaceable role in conducting long-term, time-domain astronomical research. To preserve and explore these valuable original astronomical observational data, Shanghai astronomical observatory has organized the transportation of plates, taken during nighttime observations from various stations across the country, to the Sheshan Plate Archive for centralized preservation. For the first time, plate information statistics were calculated. On this basis, the plates were cleaned and digitally scanned, and finally digitized images were acquired for 2.,314 plates. In this study, using Gaia DR2.as the reference star catalog, astrometric processing was carried out successfully on 15,696 single-exposure plates, including object extraction, stellar identification,and plate model computation. As a result, for long focal length telescopes, such as the 40 cm double-tube refractor telescope, the 1.56 m reflector telescope at Shanghai astronomical observatory, and the 1m reflecting telescope at yunnan astronomical observatory, the astrometric accuracy obtained for their plates is approximately 0."1–0."3. The distribution of astrometric accuracy for medium and short focal length telescopes ranges from 0."3 to 1."0. The relevant data of this batch of plates, including digitized images and a stellar catalog of the plates, are archived and released by the National astronomical Data Center. Users can access and download plate data based on keywords such as station, telescope, observation year, and observed celestial coordinates.

关键词： methods data analysis-techniques image processing-astronomical databases miscellaneous-astrometry

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Long-term hemispheric variation of the flare index

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Research in Astronomy and Astrophysics 2013年第3期13卷 343-350页

作者： Song Feng lin-Hua Deng Shi-Chun Xu Computer Technology Application Key Lab of yunnan Province and Faculty of Information Engineering and Automation Kunming University of Science and Technology Key Laboratory of Solar Activity National Astronomical Observatories Chinese Academy of Sciences National astronomical observatories / {2. astronomical observatory Chinese Academy of Sciences University of chinese academy of sciences kunming Institute of Physics

The long-term hemispheric variation of the flare index is investigated. It is found that, （1） the phase difference of the flare index between the northern and southern hemispheres is about 6-7 months, which is near the time delay between flare activity and sunspot activity; （2. both the dominant and phase-leading hemisphere of the flare index is the northern hemisphere in the considered time interval, implying that the hemispheric asynchrony of solar activity has a close connection with the N-S asymmetry of solar activity.

关键词： Sun: activity -- Sun: flares -- methods: data analysis

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The force-free dipole magnetosphere in nonlinear electrodynamics

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Research in Astronomy and Astrophysics 2020年第3期20卷 136-141页

作者： Hui-Quan Li Xiao-lin Yang Jian-Cheng Wang 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

Quantum electrodynamics(QED)effects may be included in physical processes of magnetar and pulsar magnetospheres with strong magnetic *** the quantum corrections,Maxwell electrodynamics is modified to nonlinear *** this work,we study the force-free magnetosphere in nonlinear electrodynamics in a general *** pulsar equation describing a steady and axisymmetric magnetosphere is derived,which now admits solutions with *** derive the first-order nonlinear corrections to the near-zone dipole magnetosphere in some popular nonlinear effective *** field lines of the corrected dipole tend to converge on the rotational axis so that the fields in the polar region are stronger compared to the pure dipole case.

关键词： stars: neutron stars: magnetars stars: magnetic field

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NSVS 012.6630:a detached binary with a close-in companion

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Research in Astronomy and Astrophysics 2018年第9期18卷 123-132页

作者： Bin Zhang Sheng-Bang Qian Nian-Ping Liu Wen-Ping Liao Li-Ying Zhu Ai-jun Dong Qi-jun Zhi yunnan observatories Chinese Academy of SciencesKunming 650216China Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China University of chinese academy of sciences Beijing 100049China School of Physics and Electronic Science Guizhou Normal UniversityGuiyang 550001China

New photometric observations of NS VS 012.6630 were performed and two sets of fourcolor（B, V, Rc, Ic） light curves（LCs） were obtained. Using the 2.13 version of the Wilson-Devinney（W-D） code, we analyzed these data. The photometric solutions reveal that NS VS 012.6630 is an active detached eclipsing binary（EB） with a high orbital inclination（nearly 90°）. Remarkably, the temperature of the primary component（the hotter star） is higher than the secondary one, but the value of mass ratio q（M2.M1）for NS VS 012.663 is more than 1, which can be explained in that the surface of the secondary component of NSVS 012.6630 is covered with big cool starspots. Based on our new CCD mid-eclipse times and the data published until now, variations in the mid-eclipse times were reanalyzed in detail using a weighted least-squares method. It is discovered that the（O-C） diagram of the system shows a cyclic oscillation with a period of 3.61 yr and an amplitude of 0.001 d. The cyclic variation may be caused by the light-travel time effect（LTTE） due to the presence of a third companion, whose mass we calculated as M3 sin（i3） =0.11 M（⊙）. The third body may affect the orbital evolution of the central binary system by transferring angular momentum.

关键词： stars binaries close- stars binaries eclipsing-stars individual (NSVS 012.6630)

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Diffuse emission of TeV neutrinos and gamma-rays from young pulsars by photomeson interaction in the Galaxy

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Research in Astronomy and Astrophysics 2013年第9期13卷 1097-1106页

作者： Zhi-Xiong Li Gui-Fang lin Wei-Wei Na Department of Physics Yunnan University yunnan astronomical {2. National Astronomical Observatories Chinese Academy of Sciences Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Department of Physics Yuxi Normal University

It is generally believed that young, rapidly rotating pulsars are important sites of particle acceleration, in which protons can be accelerated to relativistic energy above the polar cap region if the magnetic moment is antiparallel to the spin axis （μ·Ω 〈 0）. To obtain diffuse neutrinos and gamma-rays at TeV that originate in our Galaxy, we use the Monte Carlo method to generate a sample of young pulsars with ages less than 106 yr in our galaxy; the neutrinos and high-energy gamma-rays can be produced through a photomeson process with the interaction of energetic protons and soft X-ray photons （p ＋γ→△＋→n＋π＋/p＋π0） for a single pulsar, and these X-ray photons come from the surface of the neutron star. The results suggest that the flux of diffuse neutrinos at TeV energies is lower than the background flux, indicating they are difficult to detect using current neutrino telescopes.

关键词： pulsars: general -- stars: neutron -- neutrinos and gamma-rays: stars --elementary: neutrinos

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Estimating the Size and Timing of the Maximum Amplitude of Solar Cycle 2.

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chinese Journal of Astronomy and Astrophysics 2005年第5期5卷 539-545页

作者： Ke-jun Li Peng-Xin Gao Tong.Wei Su National astronomical observatories Yunnan Observatory Chinese Academy of SciencesKunming 650011 Graduate University of chinese academy of sciences Beijing 100049

A simple statistical method is used to estimate the size and timing of maximum amplitude of the next solar cycle （cycle 2.）. Presuming cycle 2. to be a short cycle （as is more likely）, the minimum of cycle 2. should occur about December 2.06 （±2.months） and the maximum, around March 2.11 （±9 months）, and the amplitude is 189.9 ± 15.5, if it is a fast riser, or about 136, if it is a slow riser. If we presume cycle 2. to be a long cycle （as is less likely）, the minimum of cycle 2. should occur about june 2.08 （±2.months） and the maximum, about February 2.13 （±8 months） and the maximum will be about 137 or 80, according as the cycle is a fast riser or a slow riser.

关键词： Sun: activity - Sun: sunspot - Sun: prediction

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New Simulations of the X-Ray Spectra and Polarizations of Accretion-disk Corona Systems with Various Geometrical Configurations *** Description

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Research in Astronomy and Astrophysics 2022年第8期22卷 140-158页

作者： Xiao-lin Yang Jian-Cheng Wang Chu-Yuan Yang yunnan observatories Chinese Academy of Sciences396 YangfangwangKunming 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

Energetic X-ray radiations emitted from various accretion systems are widely considered to be produced by Comptonization in the hot *** corona and its interaction with the disk play an essential role in the evolution of the system and are potentially responsible for many observed ***,many intrinsic properties of the corona are still poorly understood,especially for the geometrical *** traditional spectral fitting method is not powerful enough to distinguish various *** this paper,we intend to investigate the possible configurations by modeling the polarization properties of X-ray *** geometries of the corona include the slab,sphere and *** simulations are implemented through the publicly available code,Lemon,which can deal with the polarized radiative transfer and different electron distributions *** results demonstrate clearly that the observed polarizations are dependent heavily on the geometry of the *** slab-like corona produces the highest polarization degrees(PDs),followed by the cylinder and *** of the interesting things is that the PDs first increase gradually and then decrease with the increase of photon *** slab geometry,there exists a zero-point where the polarization vanishes and the polarization angle(PA)rotates by 90°.These results may potentially be verified by the upcoming missions for polarized X-ray observations,such as IXPE and e XTP.

关键词： relativistic processes polarization X-rays:galaxies scattering radiation mechanisms:non-thermal

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Binary fraction of O and B-type stars from LAMOST data

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Research in Astronomy and Astrophysics 2021年第11期21卷 19-27页

作者： Feng Luo Yong-Heng Zhao Jiao Li Yan-jun Guo Chao Liu National astronomical observatories Chinese Academy of SciencesBeijing 100101China University of chinese academy of sciences Beijing 100049China Key Lab of Space Astronomy and Technology National Astronomical ObservatoriesBeijing 100101China yunnan observatories Chinese Academy of SciencesKunming 650011China

Abstract:Binary stars play an important role in the evolution of stellar *** intrinsic binary fraction(fbin)of O and B-type(OB)stars in LAMOST DR5 was investigated in this *** employed a cross-correlation approach to estimate relative radial velocities for each of the stellar *** algorithm described by Sana et al.(2.13)was implemented and several simulations were made to assess the performance of the *** binary fraction of the OB stars is estimated through comparing the unidistribution between observations and simulations with the Kolmogorov-Smirnov *** show that it is reliable for stars most of whom have six,seven and eight repeated *** uncertainty of orbital parameters of binarity becomes larger when observational frequencies *** adopting the fixed power exponents ofπ=-0.45 andκ=-1 for period and mass ratio distributions,respectively,we obtain that fbin=0.4-0.06+0.05 for the samples with more than three *** we consider the full samples with at least two observations,the binary fraction turns out to be 0.37-0.03+*** two results are consistent with each other in 1σ.

关键词： binaries:spectroscopic techniques:radial velocities stars:early-type

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Detecting and Monitoring Tidal Dissipation of Hot Jupiters in the Era of SiTian

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Research in Astronomy and Astrophysics 2022年第5期22卷 36-46页

作者： Fan Yang Wei Wang Xing Wei Hui Zhang Ji-lin Zhou Su-Su Shan Jie Zheng Wei-Kai Zong Ming Yang Yu Bai Song Wang Jia-Chen Zheng Yu-Ru Xu Yu-Feng Li You-jun Lu Ji-Feng Liu Department of Astronomy Beijing Normal UniversityBeijing 100875China Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China School of Astronomy and Space Science Nanjing UniversityNanjing 210023China

Transit Timing Variation(TTV)of hot Jupiters provides direct observational evidence of planet tidal *** tidal dissipation through TTV needs high precision transit timings and long timing *** this work,we predict and discuss the potential scientific contribution of the SiTian Survey in detecting and analyzing exoplanet *** develop a tidal dissipation detection pipeline for the SiTian Survey that aims at time-domain astronomy with 72. m optical *** pipeline includes the modules of light curve deblending,transit timing acquisition and TTV *** is capable of detecting more than 2.,000 exoplanets among which we expect~50 sources to show evidence of tidal *** present detection and analysis of tidal dissipating targets,based on simulated SiTian light curves of XO-3b and WASP-161 *** transit light curve modeling gives consistent results within 1σto input values of simulated light ***,the parameter uncertainties predicted by Markov Chain Monte Carlo are consistent with the distribution obtained from simulating and modeling the light curve 1000 *** timing precision of SiTian observations is~0.5 minutes with one transit *** show that differences between TTV origins,e.g.,tidal dissipation,apsidal precession and multiple planets,would be significant,considering the timing precision and *** detection rate of tidal dissipating hot Jupiters would answer a crucial question of whether the planet migrates at an early formation stage or random stages due to perturbations,e.g.,planet scattering or secular *** identified targets would be constructive given that the sample would extend tenfold.

关键词： planets and satellites gaseous planets-planets and satellites physical evolution-planets and satellites dynamical evolutionand stability-planetsandsatellites detection

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Probing primordial gravitational waves: Ali CMB Polarization Telescope

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National Science Review 2019年第1期6卷 145-154页

作者： Hong Li Si-Yu Li Yang Liu Yong-Ping Li Yifu Cai Mingzhe Li Gong-Bo Zhao Cong-Zhan Liu Zheng-Wei Li He Xu Di Wu Yong-Jie Zhang Zu-Hui Fan Yong-Qiang Yao Chao-lin Kuo Fang-jun Lu Xinmin Zhang Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Theoretical Physics Division Institute of High Energy PhysicsChinese Academy of Sciences University of chinese academy of sciences CAS Key Laboratory for Researches in Galaxies and Cosmology Department of AstronomyUniversity of Scienceand Technology of China Interdisciplinary Center for Theoretical Study University of Science and Technology of China National astronomical observatories Chinese Academy of Sciences Institute of Cosmology& Gravitation University of Portsmouth Key Laboratory of Particle Astrophysics Institute of High EnergyPhysics Chinese Academy of Sciences Key Laboratory of Particle Astrophysics Institute of High Energy Physics ChineseAcademy of Sciences Department of Astronomy School of Physics Peking University Physics Department Stanford University

In this paper, we will give a general introduction to the Ali CMB Polarization Telescope(Ali CPT) project,which is a Sino–US joint project led by the Institute of High Energy Physics and involves many different institutes in china. It is the first ground-based Cosmic Microwave Background(CMB) polarization experiment in china and an integral part of china’s Gravitational-wave Program. The main scientific goal of the Ali CPT project is to probe the primordial gravitational waves(PGWs) originating from the very early Universe. The AliCPT project includes two stages. The first stage, referred to as AliCPT-1, is to build a telescope in the Ali region of Tibet at an altitude of 52.0 meters. Once completed, it will be the highest ground-based CMB observatory in the world and will open a new window for probing PGWs in the northern hemisphere. The AliCPT-1 telescope is designed to have about 7000 transition-edge sensor detectors at 95 GHz and 150 GHz. The second stage is to have a more sensitive telescope(Ali CPT-2. with more than 2. 000 detectors. Our simulations show that AliCPT will improve the current constraint on the tensor-to-scalar ratio r by one order of magnitude with three years’ observation. Besides the PGWs, Ali CPT will also enable a precise measurement of the CMB rotation angle and provide a precise test of the CPT symmetry. We show that three years’ observation will improve the current limit by two orders of magnitude.

关键词： primordial gravitational waves cosmic microwave background Ali CMB Polarization Telescope

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