Publications of the Pulkovo Observatory最新文献

Calculation of the Stokes parameters at propagation of radiation in magnetized atmosphere 计算磁化大气中辐射传播时的斯托克斯参数

Publications of the Pulkovo Observatory Pub Date : 2024-06-01 DOI: 10.31725/0367-7966-2024-233-58-67

N. Silant'ev, G. Alekseeva, Yu.K. Ananjevskaya

引用次数: 0

On the estimate of the stellar wind velocity of the massive component in OAO 1657-415 关于 OAO 1657-415 中大质量成分的恒星风速估算

Publications of the Pulkovo Observatory Pub Date : 2024-06-01 DOI: 10.31725/0367-7966-2024-233-34-38

N. Ikhsanov, V.Yu. Kim, N. Beskrovnaya

引用次数: 0

Impact of the equipment change at the Pulkovo GNSS station PULK on results of observations 普尔科沃全球导航卫星系统 PULK 站设备变化对观测结果的影响

Publications of the Pulkovo Observatory Pub Date : 2024-06-01 DOI: 10.31725/0367-7966-2024-233-51-57

Z.M. Malkin

引用次数: 0

Analysis of regularity/chaoticity of the Globular ckusters dynamics in the central region of the Milky Way 银河系中心区域球状星团动力学的规律性/混乱性分析

Publications of the Pulkovo Observatory Pub Date : 2024-06-01 DOI: 10.31725/0367-7966-2024-233-1-28

A. Bajkova, A.A. Smirnov, V. Bobylev

{"title":"Analysis of regularity/chaoticity of the Globular ckusters dynamics in the central region of the Milky Way","authors":"A. Bajkova, A.A. Smirnov, V. Bobylev","doi":"10.31725/0367-7966-2024-233-1-28","DOIUrl":"https://doi.org/10.31725/0367-7966-2024-233-1-28","url":null,"abstract":"We analyzed the regularity/chaoticity of the orbits of 45 globular clusters in the central region of the Galaxy with a radius of 3.5 kpc, which are subject to the greatest influence from an elongated rotating bar. Various analysis methods were used, namely, methods for calculating the maximum characteristic Lyapunov exponents, the method of Poincaré sections, the frequency method based on the calculation of fundamental frequencies, as well as the visual assessment method. Bimodality was discovered in the histogram of the distribution of positive Lyapunov exponents, calculated in the classical version, without renormalization of the shadow orbit, which makes it possible to implement a probabilistic method of GC classification. To construct the orbits of globular clusters, we used a gravitational potential model with a bar in the form of a triaxial ellipsoid, described in detail in the work of Bajkova et al., Izvestiya GAO in Pulkovo, 2023, 228, 1. The following bar parameters were adopted: mass 1010M⊙, semimajor axis length 5 kpc, bar viewing angle 25o, rotation speed 40 km s−1 kpc−1. To form the 6D-phase space required for orbit integration, the most accurate astrometric data to date from the Gaia satellite (EDR3) (Vasiliev, Baumgardt, 2021), as well as new refined average distances to globular clusters (Baumgardt, Vasiliev, 2021) were used. A classification is made of globular clusters with regular and chaotic dynamics. As the analysis showed, globular clusters with small pericentric distances and large eccentricities are most susceptible to the influence of the bar and demonstrate the greatest chaos. It is shown that the results of classifying globular clusters by the nature of their orbital dynamics, obtained using the various methods of analysis considered in the work, correlate well with each other.","PeriodicalId":503631,"journal":{"name":"Publications of the Pulkovo Observatory","volume":"127 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141406159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The influence of the rotation speed and shape of an asteroid on the magnitude of disturbances in its rotational dynamics during close approach to the Earth 小行星的旋转速度和形状对其接近地球时旋转动力学扰动幅度的影响

Publications of the Pulkovo Observatory Pub Date : 2024-06-01 DOI: 10.31725/0367-7966-2024-233-39-50

K. Lobanova, A. V. Melnikov

{"title":"The influence of the rotation speed and shape of an asteroid on the magnitude of disturbances in its rotational dynamics during close approach to the Earth","authors":"K. Lobanova, A. V. Melnikov","doi":"10.31725/0367-7966-2024-233-39-50","DOIUrl":"https://doi.org/10.31725/0367-7966-2024-233-39-50","url":null,"abstract":"By means of numerical experiments, the influence of the value of the asteroid’s own rotational velocity, orientation of the axis of rotation, and figure parameters on the magnitude of perturbations in its rotational dynamics arising during close approach to the Earth is studied. Two cases are considered: 1) asteroid (99942) Apophis with a relatively slow rotation (period ≈ 30 h) and 2) asteroid 2012 TC4, which has a fast rotation (period ≈ 12 min). It was found that in the case of asteroids with slow rotation, perturbations can be large: in the case of Apophis, when approaching the Earth in 2029, changes in the rotational period ∆P may reach tens of hours, and deviations in the orientation of the axis of rotation ∆γ — tens of degrees. For fast-rotating asteroids, the perturbations are very small: in the case of asteroid 2012 TC4 at its approach to the Earth in 2017, |∆P | < 10−5 min, |∆γ| < 0.01◦. It is shown that for asteroids with slow rotation, the uncertainty in the determination of asteroid figure parameters (moments of inertia) can lead to noticeable inaccuracies in the estimation of perturbation magnitudes. The uncertainty in the knowledge of the figure parameters of a fast-rotating asteroid practically does not affect the estimation of perturbations in its rotational dynamics. In the case of Apophis, changes in the rotational velocity and orientation of the axis of rotation during the upcoming 2029 approach to the Earth may lead to a decrease in the value of the parameter A2, which characterizes the Yarkovsky effect, to −1.5 · 10−14 a.u./d2, or to an increase up to −3.5 · 10−14 a.u./d2. Perturbations in the rotational dynamics of asteroid 2012 TC4 during its approach to the Earth in 2017 did not affect the value of parameter A2.","PeriodicalId":503631,"journal":{"name":"Publications of the Pulkovo Observatory","volume":"33 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141410040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The dynamics of the atmospheric precipitable water vapor on GNSS observations over the territory of the East European Craton 东欧克拉通地区全球导航卫星系统观测到的大气可降水水汽动态

Publications of the Pulkovo Observatory Pub Date : 2024-06-01 DOI: 10.31725/0367-7966-2024-233-29-33

V.L. Gorshkov, N.V. Scherbakova

引用次数: 0