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The atmospheric model of neural networks based on the improved Levenberg-Marquardt algorithm 基于改进Levenberg-Marquardt算法的神经网络大气模型
IF 0.7 4区 物理与天体物理
Open Astronomy Pub Date : 2021-01-01 DOI: 10.1515/astro-2021-0003
Wenhui Cui, W. Qu, Min Jiang, Gang Yao
{"title":"The atmospheric model of neural networks based on the improved Levenberg-Marquardt algorithm","authors":"Wenhui Cui, W. Qu, Min Jiang, Gang Yao","doi":"10.1515/astro-2021-0003","DOIUrl":"https://doi.org/10.1515/astro-2021-0003","url":null,"abstract":"Abstract Traditional atmospheric models are based on the analysis and fitting of various factors influencing the space atmosphere density. Neural network models do not specifically analyze the polynomials of each influencing factor in the atmospheric model, but use large data sets for network construction. Two traditional atmospheric model algorithms are analyzed, the main factors affecting the atmospheric model are identified, and an atmospheric model based on neural networks containing various influencing factors is proposed. According to the simulation error, the Levenberg-Marquardt algorithm is used to iteratively realize the rapid network weight correction, and the optimal neural network atmospheric model is obtained. The space atmosphere is simulated and calculated with an atmospheric model based on neural networks, and its average error rate is lower than that of traditional atmospheric models such as the DTM2013 model and the MSIS00 model. At the same time, the calculation complexity of the atmospheric model based on the neural networks is significantly simplified than that of the traditional atmospheric model.","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44357716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Astrometry and photometry of digitized plates of Baldone Schmidt telescope 巴尔东·施密特望远镜数字化底片的天体测量与光度学研究
IF 0.7 4区 物理与天体物理
Open Astronomy Pub Date : 2021-01-01 DOI: 10.1515/astro-2021-0002
I. Eglitis, V. Andruk
{"title":"Astrometry and photometry of digitized plates of Baldone Schmidt telescope","authors":"I. Eglitis, V. Andruk","doi":"10.1515/astro-2021-0002","DOIUrl":"https://doi.org/10.1515/astro-2021-0002","url":null,"abstract":"Abstract During the 40-year photographic period of astronomical observations, the Baldone Astrophysical Observatory has accumulated more than 22,000 direct and 2,500 spectral images. In 2018, the digitization of direct astrophoto images with a resolution of 1200 dpi was completed. A processing methodology for obtaining the equatorial coordinates and photometric characteristics of the objects recorded in digitized astronegatives using the LINUX/MIDAS/ROMAFOT environment has been developed at the Main Astronomical Observatory of the National Academy of Sciences of Ukraine. Program package with success already works in seven observatories. A description of the operation of this program complex in stages and analysis of the obtained results is given. The steps describe the astrometric and photometric reduction process of digital records, as well as the reduction of the obtained instrumental magnitudes to the Johnson UBVR photometric system. The methodology of characteristic curve construction in the case of one exposure is described in detail. From all digitized astrophotoplates to date Approximately 2200 V film negatives, 300 U plates and several R, B plates were processed. As a result, catalogs of the positions and magnitudes of Pluto, 1848 asteroids and comets were obtained. 31 new positions were recorded in the VizieR Pluto catalog VI/155. It was found that the root-mean-square errors of the reduction of the measured coordinates to the equatorial coordinate system of the Tycho-2 catalog have values σRA,DEC= 0.1-0.2”, and the root-mean-square errors of the reduction of instrumental photometric quantities m to the Johnson system of stellar UBVR-values are also in within σUBVR = 0.1 − 0.2m.","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/astro-2021-0002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44058674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
PRESTALINE: a package for simulation and analysis of molecular spectra of star forming regions PRESTALINE:一个用于模拟和分析恒星形成区域分子光谱的软件包
IF 0.7 4区 物理与天体物理
Open Astronomy Pub Date : 2021-01-01 DOI: 10.1515/astro-2021-0012
G. Van Looveren, O. Kochina, D. Wiebe
{"title":"PRESTALINE: a package for simulation and analysis of molecular spectra of star forming regions","authors":"G. Van Looveren, O. Kochina, D. Wiebe","doi":"10.1515/astro-2021-0012","DOIUrl":"https://doi.org/10.1515/astro-2021-0012","url":null,"abstract":"Abstract We present the PRESTALINE package, a novel tool to simulate and analyse spectra of star forming objects. PRESTALINE allows for a direct comparison of theoretical models with observations and simplifies an analysis of observed spectra. This allows researchers to estimate physical conditions in a studied object and to interpret its chemical composition in a quantitative way. The goal of the project is to set up a consistent framework which would bridge a gap between theoretical studies and observations of star forming regions. In this paper, we present the results of applying PRESTALINE to the test object DR21(OH) and discuss the project general possibilities.","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43619863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Biermann battery as a source of astrophysical magnetic fields 比尔曼电池作为天体物理磁场的来源
IF 0.7 4区 物理与天体物理
Open Astronomy Pub Date : 2021-01-01 DOI: 10.1515/astro-2021-0017
E. Mikhailov, R. Andreasyan
{"title":"Biermann battery as a source of astrophysical magnetic fields","authors":"E. Mikhailov, R. Andreasyan","doi":"10.1515/astro-2021-0017","DOIUrl":"https://doi.org/10.1515/astro-2021-0017","url":null,"abstract":"Abstract A large number of galaxies have large-scale magnetic fields which are usually measured by the Faraday rotation of radio waves. Their origin is usually connected with the dynamo mechanism which is based on differential rotation of the interstellar medium and alpha-effect characterizing the helicity of the small-scale motions. However, it is necessary to have initial magnetic field which cannot be generated by the dynamo. One of the possible mechanisms is connected with the Biermann battery which acts because of different masses of protons and electrons passing from the central object. They produce circular currents which induce the vertical magnetic field. As for this field we can obtain the integral equation which can be solved by simulated annealing method which is widely used in different branches of mathematics","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67441284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Possibilities of velocity field analysis from Hinode SOT/SP data 利用Hinode SOT/SP数据进行速度场分析的可能性
IF 0.7 4区 物理与天体物理
Open Astronomy Pub Date : 2021-01-01 DOI: 10.1515/astro-2021-0026
S. G. Mozharovsky
{"title":"Possibilities of velocity field analysis from Hinode SOT/SP data","authors":"S. G. Mozharovsky","doi":"10.1515/astro-2021-0026","DOIUrl":"https://doi.org/10.1515/astro-2021-0026","url":null,"abstract":"Abstract The possibility of analyzing the line of sight (LOS) velocity and its gradient at each point of the Hinode SOT/SP maps using bisector analysis is revealed. A technique for obtaining such gradient is described. To estimate the velocity gradient, it is necessary to know both the velocity value and the layer height to which the bisector point is responded. We have constructed and tested a method to determine this height. We found velocities at the same heights for lines Fe I λ 6301, 6302 Å averaged over the whole map. It turned out that these velocities have some difference that changes with height and time. The error in the estimating of average velocity for the whole map is 2 m·s−1. It follows that the wavelengths of lines 6301 and 6302 given in the NIST tables may differ from the real ones at 5.5 mÅ. Or there is an inaccuracy in the spectrograph dispersion specified in the FITS files. As an example, the curves of changes with the height of the LOS velocity and its gradient were constructed both for points of the whole map and for subsets of the hottest and coldest points.","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44809877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
The near-infrared observations at the Tower Solar Telescope TST-2 of the Crimean Astrophysical Observatory 克里米亚天体物理天文台塔式太阳望远镜TST-2的近红外观测
IF 0.7 4区 物理与天体物理
Open Astronomy Pub Date : 2021-01-01 DOI: 10.1515/astro-2021-0030
O. Andreeva, V. Malashchuk
{"title":"The near-infrared observations at the Tower Solar Telescope TST-2 of the Crimean Astrophysical Observatory","authors":"O. Andreeva, V. Malashchuk","doi":"10.1515/astro-2021-0030","DOIUrl":"https://doi.org/10.1515/astro-2021-0030","url":null,"abstract":"Abstract Observations in the near-infrared wavelength range have been regularly carried out at the Crimean Astrophysical Observatory (CrAO) on the Tower Solar Telescope (TST-2). It began in the late 1990s by putting into operation the Universal Spectrophotometer (USPh) at the TST-2 and it continues up to the present time. In 2020 the observation process was modernized - the mirror control electronics and software were replaced. Work is currently underway to create a catalog of solar disk images obtained before the modernization of TST-2. Here we present fragments of the catalog - several examples of a full solar disk in He i 1083 nm from the USPh/TST-2 instrument and a brief description of the future catalog.","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48151237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Future of the General Catalogue of Variable Stars from the Experience of Recent Name-lists 从最近的星表经验看变星总表的未来
IF 0.7 4区 物理与天体物理
Open Astronomy Pub Date : 2021-01-01 DOI: 10.1515/astro-2021-0016
N. Samus, E. Kazarovets, O. V. Durlevich, Natalia N. Kireeva, E. Pastukhova, Anton V. Khruslov
{"title":"Future of the General Catalogue of Variable Stars from the Experience of Recent Name-lists","authors":"N. Samus, E. Kazarovets, O. V. Durlevich, Natalia N. Kireeva, E. Pastukhova, Anton V. Khruslov","doi":"10.1515/astro-2021-0016","DOIUrl":"https://doi.org/10.1515/astro-2021-0016","url":null,"abstract":"Abstract We briefly outline the history of the General Catalogue of Variable Stars (GCVS) and the New Catalogue of Suspected Variable Stars (NSV catalogue). Recently, we have completed a revision of the NSV catalogue. Positional information was checked for all its stars and, in many cases, new photometric data were added. As a result, one third of all NSV stars have been transferred to the GCVS. Having determined equatorial coordinates for variable stars in globular star clusters, we began to add them to the GCVS. Two Name-lists published so far contain more than 1700 variable stars in 36 globular clusters; an additional Name-list (about 900 variable stars in 27 globular clusters) will be published before the end of 2021. We discuss problem cases in the literature and in the Catalogue of Variable Stars in Galactic Globular Clusters revealed during our preparation of the Name-lists. The future of traditional catalogues of variable stars (GCVS; AAVSO Variable-star Data Index VSX) is discussed.","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46304175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
The Mg/Fe ratio of silicate minerals in the meteoritic materials and in the circumstellar environment: A case study for the chondritic-like composition 陨石材料和星周环境中硅酸盐矿物的Mg/Fe比：以球粒陨石类成分为例
IF 0.7 4区 物理与天体物理
Open Astronomy Pub Date : 2021-01-01 DOI: 10.1515/astro-2021-0006
P. Fűtő, J. Vanyó, I. Simonia, J. Sztakovics, M. Nagy, A. Gucsik, B. Döncző, Z. Kertész, Richárd Novák, Á. Csámer
{"title":"The Mg/Fe ratio of silicate minerals in the meteoritic materials and in the circumstellar environment: A case study for the chondritic-like composition","authors":"P. Fűtő, J. Vanyó, I. Simonia, J. Sztakovics, M. Nagy, A. Gucsik, B. Döncző, Z. Kertész, Richárd Novák, Á. Csámer","doi":"10.1515/astro-2021-0006","DOIUrl":"https://doi.org/10.1515/astro-2021-0006","url":null,"abstract":"Abstract Kaba meteorite as a reference material (one of a least metamorphosed and most primitive carbonaceous chondrites fell on Earth) was chosen for this study providing an adequate background for study of the protoplanetary disk or even the crystallization processes of the Early Solar System. Its olivine minerals (forsterite and fayalite) and their Mg/Fe ratio can help us to understand more about the planet formation mechanism and whether or not the metallic constitutes of the disk could be precursors for the type of planets in the Solar System. A multiple methodological approach such as a combination of the scanning electron microscope, optical microscope, Raman spectroscopy and electron microprobe of the olivine grains give the Fe/Mg ratio database. The analyses above confirmed that planet formation in the protoplanetary disk is driven by the mineralogical precursors of the crystallization process. On the other hand, four nebulae mentioned in this study provide the astronomical data confirming that the planet formation in the protoplanetary disk is dominated or even driven by the metallic constituents.","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48894124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Fitting procedure for estimating interstellar extinction at high galactic latitudes 估算银河系高纬度星际消光的拟合程序
IF 0.7 4区 物理与天体物理
Open Astronomy Pub Date : 2021-01-01 DOI: 10.1515/astro-2021-0022
A. Avdeeva, D. Kovaleva, O. Malkov, Alexey Nekrasov
{"title":"Fitting procedure for estimating interstellar extinction at high galactic latitudes","authors":"A. Avdeeva, D. Kovaleva, O. Malkov, Alexey Nekrasov","doi":"10.1515/astro-2021-0022","DOIUrl":"https://doi.org/10.1515/astro-2021-0022","url":null,"abstract":"Abstract We determine the interstellar extinction in the selected high-latitude areas of the sky based on Gaia EDR3 astrometry and photometry and spectroscopic data from RAVE survey. We approximate the results with the cosecant law in each area thus deriving the parameters of the barometric formula for different lines of sight. The distribution of the parameters over the entire sky is described using spherical harmonics. As a result, we get a mathematical description of the interstellar visual extinction for different lines of sight and distances from the Sun which can be used for estimating interstellar extinction.","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43468107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Prevention of NEO hazard: the Russian approach 防止近地天体危害：俄罗斯的做法
IF 0.7 4区 物理与天体物理
Open Astronomy Pub Date : 2021-01-01 DOI: 10.1515/astro-2021-0007
E. Pavlova, V. Voropaev
{"title":"Prevention of NEO hazard: the Russian approach","authors":"E. Pavlova, V. Voropaev","doi":"10.1515/astro-2021-0007","DOIUrl":"https://doi.org/10.1515/astro-2021-0007","url":null,"abstract":"Abstract Russian Academy of Sciences (RAS) is actively working to solve the problem of preventing Near-Earth Object (NEO) hazard. The article provides the goals and objectives of preventing NEO hazard, as well as ways to achieve them. The described ways of achieving the goal are applied in RAS best. The current state and prospects of the Russian contribution to the prevention of NEO hazard are considered. Statistical data on the dynamics of observation of minor planets by Russian telescopes is presented. The structure of the NEO part of hazardous situations classifier developed by Keldysh Institute of Applied Mathematics (KIAM RAS) and structure of perspective National System Security of space activities in outer space are presented, including the system’s response to event classified as dangerous. The article is accompanied by illustrations of potentially hazardous objects in the sky, made by telescopes of the International Network of Optical Telescopes (ISON), coordinated by the KIAM RAS.","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41957462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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