Physical properties of the trans-Neptunian object (38628) Huya from a multi-chord stellar occultation
Physical properties of the trans-Neptunian object (38628) Huya from a multi-chord stellar occultation
复制标题
来自多弦恒星掩星的海王星外天体 (38628) Huya 的物理特性
DOI：
10.1051/0004-6361/202141546
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
M. Zejmo
中科院分区：
文献类型：
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作者：
P. Santos;J. L. Ortiz;B. Sicardy;M. Popescu;G. Benedetti;N. Morales;M. Vara;J. Camargo;C. Pereira;F. Rommel;M. Assafin;J. Desmars;F. Braga;R. Duffard;J. Oliveira;R. Vieira;E. Fern'andez;B. Morgado;M. Acar;S. Anghel;E. Atalay;A. Atecs;H. Bakics;V. Bakics;Z. Eker;O. Erece;S. Kaspi;C. Kayhan;S. Kılıç;Y. Kilic;I. Manulis;D. Nedelcu;M. S. Niaei;G. Nir;E. Ofek;T. Ozisik;E. Petrescu;O. Şatır;A. Solmaz;A. Sonka;M. Tekes;O. Unsalan;C. Yeşi̇lyaprak;R. Anghel;D. Bertecsteanu;L. Curelaru;C. Dănescu;V. Dumitrescu;R. Gherase;L. Hudin;A. Stoian;J. Tercu;R. Truta;V. Turcu;C. Vantdevara;I. Belskaya;T. Dementiev;K. Gazeas;S. Karampotsiou;V. Kashuba;C. Kiss;N. Koshkin;O. Kozhukhov;Y. Krugly;J. Lecacheux;A. Pál;C. Puskullu;R. Szakáts;V. Zhukov;D. Bamberger;B. Mondon;C. Perell'o;A. Pratt;C. Schnabel;A. Selva;J. Teng;K. Tigani;V. Tsamis;C. Weber;G. Wells;S. Kalkan;V. Kudak;A. Marciniak;W. Ogłoza;T. Ozdemir;E. Pakštienė;V. Perig;M. Zejmo
上下文。作为我们旨在获得海王星外天体(TNO)精确物理性质的国际计划的一部分，我们预测了由TNO(38628)HUYA对恒星Gaia DR2 4352760586390566400(mG=11.5mag.)的恒星掩星。2019年3月18日。在为获得天体测量数据而进行的广泛观测活动之后，我们更新了预测，发现它有利于中欧。因此，我们在这个地区动员了500名专业和业余天文学家，最终用分布在欧洲和亚洲18个地点的21台望远镜探测到了这一掩星。这使虎牙事件成为TNO观测到的最好的恒星掩星之一，就弦的数量而言。目标。我们工作的目的是利用多弦掩星获得的观测数据来确定TNO(38628)HUYA的精确大小、形状和几何反照率。我们还旨在提供对这种TNO的密度和其他内部性质的限制。方法：研究方法。虎牙对掩星的21次积极探测使我们能够获得分离良好的和弦，这使得我们能够以公里精度为掩星瞬间的肢体(即瞬时肢体)拟合一个椭圆。结果。利用掩星数据得到最佳椭圆拟合的投影半长轴和短轴为(a‘，b’)=(217.6±3.5公里，194.1±6.1公里)，短轴的位置角为P‘=55.2◦±9.1.由此拟合出的面积当量直径为411.0±7.3km.这一直径与由辐射测量技术得到的虎牙的等效直径(D=406±16公里)是一致的。从这个瞬时边缘，我们得到了虎牙的几何反照率(pV=0。079±0。004)，我们探索了可能的三维形状和对这种TNO质量密度的限制。我们没有通过这次掩星探测到虎牙的卫星，但利用掩星数据限制了虎牙周围环或碎片的存在。我们还推导出了假设类冥王星的全球大气的上限约为p SURF=10NBAR。
Context. As part of our international program aimed at obtaining accurate physical properties of trans-Neptunian objects (TNOs), we predicted a stellar occultation by the TNO (38628) Huya of the star Gaia DR2 4352760586390566400 (m G = 11.5 mag.) on March 18, 2019. After an extensive observational campaign geared at obtaining the astrometric data, we updated the prediction and found it favorable to central Europe. Therefore, we mobilized half a hundred of professional and amateur astronomers in this region and the occultation was finally detected by 21 telescopes located at 18 sites in Europe and Asia. This places the Huya event among the best ever observed stellar occultation by a TNO in terms of the number of chords. Aims. The aim of our work is to determine an accurate size, shape, and geometric albedo for the TNO (38628) Huya by using the observations obtained from a multi-chord stellar occultation. We also aim to provide constraints on the density and other internal properties of this TNO. Methods. The 21 positive detections of the occultation by Huya allowed us to obtain well-separated chords which permitted us to fit an ellipse for the limb of the body at the moment of the occultation (i.e., the instantaneous limb) with kilometric accuracy. Results. The projected semi-major and minor axes of the best ellipse fit obtained using the occultation data are (a ′ , b ′ ) = (217.6 ± 3.5 km , 194.1 ± 6.1 km) with a position angle for the minor axis of P ′ = 55.2 ◦ ± 9.1. From this fit, the projected area-equivalent diameter is 411.0 ± 7.3 km. This diameter is compatible with the equivalent diameter for Huya obtained from radiometric techniques (D = 406 ± 16 km). From this instantaneous limb, we obtained the geometric albedo for Huya ( p V = 0 . 079 ± 0 . 004) and we explored possible three-dimensional shapes and constraints to the mass density for this TNO. We did not detect the satellite of Huya through this occultation, but the presence of rings or debris around Huya was constrained using the occultation data. We also derived an upper limit for a putative Pluto-like global atmosphere of about p surf = 10 nbar.