Proceedings of the International Astronomical Union最新文献_第2页

Apsidal alignment in migrating dust - Crescent features caused by eccentric planets 迁移尘埃的侧位排列——偏心行星引起的新月特征

Proceedings of the International Astronomical Union Pub Date : 2021-10-01 DOI: 10.1017/S1743921322000035

M. Sommer, P. Pokorný, H. Yano, R. Srama

引用次数: 0

Noise, friction and the radial-orbit instability in anisotropic stellar systems: stochastic N–body simulations 各向异性恒星系统中的噪声、摩擦和径向轨道不稳定性:随机n体模拟

Proceedings of the International Astronomical Union Pub Date : 2021-10-01 DOI: 10.1017/S1743921321001484

P. Di Cintio, L. Casetti

引用次数: 0

New results on orbital resonances 轨道共振的新结果

Proceedings of the International Astronomical Union Pub Date : 2021-10-01 DOI: 10.1017/S1743921321001411

R. Malhotra

{"title":"New results on orbital resonances","authors":"R. Malhotra","doi":"10.1017/S1743921321001411","DOIUrl":"https://doi.org/10.1017/S1743921321001411","url":null,"abstract":"Abstract Perturbative analyses of planetary resonances commonly predict singularities and/or divergences of resonance widths at very low and very high eccentricities. We have recently re-examined the nature of these divergences using non-perturbative numerical analyses, making use of Poincaré sections but from a different perspective relative to previous implementations of this method. This perspective reveals fine structure of resonances which otherwise remains hidden in conventional approaches, including analytical, semi-analytical and numerical-averaging approaches based on the critical resonant angle. At low eccentricity, first order resonances do not have diverging widths but have two asymmetric branches leading away from the nominal resonance location. A sequence of structures called “low-eccentricity resonant bridges” connecting neighboring resonances is revealed. At planet-grazing eccentricity, the true resonance width is non-divergent. At higher eccentricities, the new results reveal hitherto unknown resonant structures and show that these parameter regions have a loss of some – though not necessarily entire – resonance libration zones to chaos. The chaos at high eccentricities was previously attributed to the overlap of neighboring resonances. The new results reveal the additional role of bifurcations and co-existence of phase-shifted resonance zones at higher eccentricities. By employing a geometric point of view, we relate the high eccentricity phase space structures and their transitions to the shapes of resonant orbits in the rotating frame. We outline some directions for future research to advance understanding of the dynamics of mean motion resonances.","PeriodicalId":20590,"journal":{"name":"Proceedings of the International Astronomical Union","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74993928","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

Evolution and stability of Laplace-like resonances under tidal dissipation 潮汐耗散下类拉普拉斯共振的演化与稳定性

Proceedings of the International Astronomical Union Pub Date : 2021-10-01 DOI: 10.1017/S1743921322000552

A. Celletti, E. Karampotsiou, C. Lhotka, G. Pucacco, M. Volpi

{"title":"Evolution and stability of Laplace-like resonances under tidal dissipation","authors":"A. Celletti, E. Karampotsiou, C. Lhotka, G. Pucacco, M. Volpi","doi":"10.1017/S1743921322000552","DOIUrl":"https://doi.org/10.1017/S1743921322000552","url":null,"abstract":"Abstract The Laplace resonance is a configuration that involves the commensurability between the mean motions of three small bodies revolving around a massive central one. This resonance was first observed in the case of the three inner Galilean satellites, Io, Europa, and Ganymede. In this work the Laplace resonance is generalised by considering a system of three satellites orbiting a planet that are involved in mean motion resonances. These Laplace-like resonances are classified in three categories: first-order (2:1&2:1, 3:2&3:2, 2:1&3:2), second-order (3:1&3:1) and mixed-order resonances (2:1&3:1). In order to study the dynamics of the system we implement a model that includes the gravitational interaction with the central body, the mutual gravitational interactions of the satellites, the effects due to the oblateness of the central body and the secular interaction of a fourth satellite and a distant star. Along with these contributions we include the tidal interaction between the central body and the innermost satellite. We study the survival of the Laplace-like resonances and the evolution of the orbital elements of the satellites under the tidal effects. Moreover, we study the possibility of capture into resonance of the fourth satellite.","PeriodicalId":20590,"journal":{"name":"Proceedings of the International Astronomical Union","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78841965","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

Dynamics around the binary system (65803) Didymos 双星系统周围的动力学(65803

Proceedings of the International Astronomical Union Pub Date : 2021-10-01 DOI: 10.1017/S1743921321001241

R. Machado Oliveira, O. Winter, R. Sfair, G. Valvano, T. Moura, G. Borderes-Motta

引用次数: 0

On the scattering and dynamical evolution of Oort cloud comets caused by a stellar fly-by 恒星飞掠引起的奥尔特云彗星的散射和动力学演化

Proceedings of the International Astronomical Union Pub Date : 2021-10-01 DOI: 10.1017/S1743921321001332

E. Pilat-Lohinger, S. Clees, M. Zimmermann, B. Loibnegger

{"title":"On the scattering and dynamical evolution of Oort cloud comets caused by a stellar fly-by","authors":"E. Pilat-Lohinger, S. Clees, M. Zimmermann, B. Loibnegger","doi":"10.1017/S1743921321001332","DOIUrl":"https://doi.org/10.1017/S1743921321001332","url":null,"abstract":"Abstract Recent GAIA observations revealed that the K-type star Gliese 710 will cross the Oort cloud in a distance between approximately 4000 and 12000 au in about 1.3 Myrs. This occurrence motivated us to study the influence of a stellar encounter on comets in the outer region of the solar system. Even if the Oort cloud extends to 100000 au from the sun, we restrict our study to the region between 30 and 25000 au where 25 million objects are distributed randomly. Comets at larger distances are not taken into account as they hardly enter the observable region after a single stellar fly-by. An overview of all objects that are scattered towards the sun for the different fly-by distances at 4000, 8000 and 12000 au shows that only a handful of objects are moving towards the sun immediately after the stellar encounter. However, a subsequent long-term study of all objects that are moved into highly eccentric motion by the stellar fly-by shows a significant increase of comets crossing Jupiter’s orbit and entering into the observable region. In addition, our study shows the first comets crossing the orbit of Earth only about 2.5 Myrs after the stellar fly-by. Thus, the impact risk for the Earth increases only some million years after the stellar fly-by.","PeriodicalId":20590,"journal":{"name":"Proceedings of the International Astronomical Union","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74950801","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: 1

A numerical criterion evaluating the robustness of planetary architectures; applications to the υ Andromedæ system 评价行星结构鲁棒性的数值准则应用程序到υ Andromedæ系统

Proceedings of the International Astronomical Union Pub Date : 2021-10-01 DOI: 10.1017/S1743921322000461

U. Locatelli, Chiara Caracciolo, M. Sansottera, M. Volpi

引用次数: 4

The Lidov-Kozai resonance at different scales 不同尺度的Lidov-Kozai共振

Proceedings of the International Astronomical Union Pub Date : 2021-10-01 DOI: 10.1017/S1743921321001423

Anne-Sophie Libert

引用次数: 0

Multiple bifurcations around 433 Eros with Harmonic Balance Method 用调和平衡法研究433爱神周围的多重分叉

Proceedings of the International Astronomical Union Pub Date : 2021-10-01 DOI: 10.1017/S1743921322000734

Leclère Nicolas, Kerschen Gaëtan, Dell’Elce Lamberto

引用次数: 0

Satellites’ orbital stability through normal forms 卫星的轨道稳定性通过正常形式

Proceedings of the International Astronomical Union Pub Date : 2021-10-01 DOI: 10.1017/S174392132100137X

Irene De Blasi, A. Celletti, C. Efthymiopoulos

引用次数: 0