The 2017 May 20$^{\rm th}$ stellar occultation by the elongated centaur (95626) 2002 GZ$_{32}$
P. Santos-Sanz, J. L. Ortiz, B. Sicardy, G. Benedetti-Rossi, N. Morales, E. Fernández-Valenzuela, R. Duffard, R. Iglesias-Marzoa, J. L. Lamadrid, N. Maícas, L. … 展开作者
P. Santos-Sanz, J. L. Ortiz, B. Sicardy, G. Benedetti-Rossi, N. Morales, E. Fernández-Valenzuela, R. Duffard, R. Iglesias-Marzoa, J. L. Lamadrid, N. Maícas, L. Pérez, K. Gazeas, J. C. Guirado, V. Peris, F. J. Ballesteros, F. Organero, L. Ana-Hernández, F. Fonseca, A. Alvarez-Candal, Y. Jiménez-Teja, M. Vara-Lubiano, F. Braga-Ribas, J. I. B. Camargo, J. Desmars, M. Assafin, R. Vieira-Martins, J. Alikakos, M. Boutet, M. Bretton, A. Carbognani, V. Charmandaris, F. Ciabattari, P. Delincak, A. Fuambuena Leiva, H. González, T. Haymes, S. Hellmich, J. Horbowicz, M. Jennings, B. Kattentidt, Cs. Kiss, R. Komžík, J. Lecacheux, A. Marciniak, S. Moindrot, S. Mottola, A. Pal, N. Paschalis, S. Pastor, C. Perello, T. Pribulla, C. Ratinaud, J. A. Reyes, J. Sanchez, C. Schnabel, A. Selva, F. Signoret, E. Sonbas, V. Alí-Lagoa
备注：
Accepted for publication in MNRAS (8-Dec.-2020), 15 pages, 9 figures
We predicted a stellar occultation of the bright star Gaia DR1 4332852996360346368 (UCAC4 385-75921) (m$_{\rm V}$= 14.0 mag) by the centaur 2002 GZ$_{32}$ for 2017 May 20$^{\rm th}$. Our latest shadow path prediction was favourable to a large region in Europe. Observations were arranged in a broad region inside the nominal shadow path. Series of images were obtained with 29 telescopes throughout Europe and from six of them (five in Spain and one in Greece) we detected the occultation. This is the fourth centaur, besides Chariklo, Chiron and Bienor, for which a multi-chord stellar occultation is reported. By means of an elliptical fit to the occultation chords we obtained the limb of 2002 GZ$_{32}$ during the occultation, resulting in an ellipse with axes of 305 $\pm$ 17 km $\times$ 146 $\pm$ 8 km. From this limb, thanks to a rotational light curve obtained shortly after the occultation, we derived the geometric albedo of 2002 GZ$_{32}$ ($p_{\rm V}$ = 0.043 $\pm$ 0.007) and a 3-D ellipsoidal shape with axes 366 km $\times$ 306 km $\times$ 120 km. This shape is not fully consistent with a homogeneous body in hydrostatic equilibrium for the known rotation period of 2002 GZ$_{32}$. The size (albedo) obtained from the occultation is respectively smaller (greater) than that derived from the radiometric technique but compatible within error bars. No rings or debris around 2002 GZ$_{32}$ were detected from the occultation, but narrow and thin rings cannot be discarded.
Material Around the Centaur (2060) Chiron from the 2018 November 28 UT Stellar Occultation
Planetary Science Institute（行星科学研究所）；Lowell Observatory（洛厄尔天文台）；Massachusetts Institute of Technology（麻省理工学院）；Deutsches SOFIA Institut（德国SOFIA研究所）；Universität Stuttgart（斯图加特大学）；SOFIA Science Center（SOFIA科学中心）；NASA Ames Research Center（NASA艾姆斯研究中心）；Trinity University（三一大学）
JWST occultation reveals unforeseen complexity in Chariklo's ring system
Instituto de Astrofísica de Andalucía, CSIC（安达卢西亚天体物理研究所，西班牙高等科学研究委员会）；Instituto de Física, Universidade Federal de Uberlândia (UFU)（乌贝兰迪亚联邦大学物理研究所）；Laboratório Interinstitucional de e-Astronomia - LIneA（机构间电子天文实验室）；Grupo de Dinâmica Orbital e Planetologia, Faculdade de Engenharia e Ciêncas de Guaratinguetá, Universidade Estadual Julio de Mesquita Filho (GDOP/FEG/UNESP)（圣保罗州立大学朱利奥·德·梅斯基塔 Filho 工程学院瓜拉廷盖塔分校轨道动力学与行星学小组）；Federal University of Rio de Janeiro - Valongo Observatory（里约热内卢联邦大学瓦隆戈天文台）；Observatório Nacional/MCTI（国家天文台/巴西科技、创新和通信部）；LIRA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Université, Univ. Paris Diderot, Sorbonne Paris Cité（巴黎天文台，PSL研究大学，法国国家科学研究中心，索邦大学，巴黎第七大学，索邦巴黎城）；Konkoly Observatory, HUN-REN Research Centre for Astronomy and Earth Sciences（孔科利天文台，匈牙利研究与创新网络地球与天文学研究中心）；CSFK, MTA Centre of Excellence, Konkoly Thege Miklós út 15-17（马塔尔·特格·米克洛斯街15-17号卓越中心孔科利天文台）；ELTE Eötvös Loránd University, Institute of Physics（罗兰·厄特沃什大学物理研究所）
The Dynamical History Of 2060 Chiron And Its Proposed Ring System
2013年，令人惊讶地发现了半人马座10199 Chariklo周围的环系统，这导致Ortiz等人重新分析了半人马座2060 Chiron的恒星掩星数据。在这项工作中，我们研究了拟议的凯龙星环系统的动力学历史，通过整合近36,000个半人马座的克隆，在太阳和四个巨行星的影响下，在时间上向后追溯了1亿年。当克隆人在半人马座地区时，所有克隆人和行星之间的近距离接触的严重程度都被记录下来，以及近距离接触之间的平均时间。我们发现严重和极端的近距离接触是非常罕见的，这使得凯龙星环系统自注入半人马座地区以来一直保持完整，我们发现这可能发生在过去的850万年内。我们的模拟产生了一个向后的动力学半衰期为0.7百万年的凯龙。研究发现，由于平均运动共振中的共振粘滞，共振跳跃克隆的半人马寿命平均是随机行走克隆的2倍。此外，我们提出的MEGNO和混沌的寿命地图的13 AU $\le a \le$ 14 AU和电子$\le$ 0.5的区域。我们证实了Chiron的当前平均轨道参数位于a-e相空间的高度混沌区域。
Instituto de Astrofísica de Andalucía-CSIC（安达卢西亚天体物理研究所-西班牙国家研究委员会）；Max-Planck-Institut für extraterrestrische Physik (MPE)（马克斯·普朗克地外物理研究所）；LESIA - Observatoire de Paris, CNRS（巴黎天文台LESIA实验室-CNRS）；Department of Physics, University of Helsinki（赫尔辛基大学物理系）
Predictions of Stellar Occultations by Haumea and the Event of 4 May 2026
Instituto de Astrofísica de Andalucía-CSIC（安达卢西亚天体物理研究所）；I.E.S Politécnico Hermenegildo Lanz（埃尔梅内吉尔多·兰茨理工学院）；NASA Ames Research Center（美国国家航空航天局艾姆斯研究中心）；Department of Space Sciences and Technologies, Faculty of Science, Akdeniz University（安塔利亚大学理学院空间科学与技术系）；Deutsches Zentrum für Astrophysik (DZA)（德国天体物理学中心）
Constraining the size, shape, and albedo of the large Trans-Neptunian Object (28978) Ixion with multi-chord stellar occultations
Instituto de Astrofísica de Andalucía, IAA-CSIC（安达卢西亚天体物理研究所）；LIRA, CNRS UMR8254, Observatoire de Paris（巴黎天文台）；Federal University of Technology – Paraná (PPGFA/UTFPR)（巴拉那联邦技术大学）；Laboratório Interinstitucional de e-Astronomia (LIneA)（跨机构电子天文学实验室）；Observatório Nacional (MCTI)（国家天文台）；LTE, Observatoire de Paris, Université PSL, Sorbonne Université, Université de Lille, LNE, CNRS（巴黎天文台）；Türkiye National Observatories, TUG（土耳其国家天文台）；The Scientific and Technological Research Council of Türkiye (TÜBİTAK)（土耳其科学与技术研究委员会）；naXys, Department of Mathematics, University of Namur（南纳慕尔大学）；Federal University of Rio de Janeiro - Observatory of Valongo（里约热内卢联邦大学瓦隆戈天文台）；Instituto de Física, Universidade Federal de Uberlândia（乌贝兰迪亚联邦大学物理研究所）；UNESP – São Paulo State University, Grupo de Dinâmica Orbital e Planetologia（圣保罗州立大学）；Institut Polytechnique des Sciences Avancées (IPSA)（高级科学理工学院）；Deutsches Zentrum für Astrophysik (DZA)（德国天体物理学中心）；Florida Space Institute, University of Central Florida（中佛罗里达大学佛罗里达太空研究所）；Department of Space Sciences and Technologies, Akdeniz University（安塔利亚大学空间科学与技术系）；Trans-Tasman Occultation Alliance (TTOA)（跨塔斯曼掩食联盟）；Institute of Astronomy and Astrophysics, University of Tübingen（蒂宾根大学天体物理学与天文学研究所）
