英仙座流星雨的摄像观测

流星的观测,除了传统的目视与照相方法外,摄像观测开始起着越来越重要的作用。摄像不仅能够记录下流星的准确方位,而且还能够很方便地获得流星出现和移动的时刻,从而具备更多的信息量。如果在不同地点记录下同一颗流星,就可以据此计算出流星在空间的轨迹以及运动的速度。     

狮子座流星雨1999年照相观测的分析

对1999年11月19日拍摄的两张狮子座流星胶片进行了分析研究照相观测比目观测记录了更多的定量信息计算了流星在胶片上显露时必须满足的运动角速度条件,求出了流星起始点仰角、流星结束点与辐射点的角距离、流星运动的角速度以及流星路径的弧长等并且得出流星在大气中的烧蚀时间仅0 65秒左右,即烧蚀的路径长约40 50公里通过在扫描仪上得到的黑白图像的处理,求得两颗流星的照相星等分别为-10.3 ± 0.2和-4.8±0.2.由此可以得到它们的质量和电子线密度.给出的处理方法,也可用于其他流星的照相观测资料处理.并且,对流星观测使用的照相镜头也进行了讨论.     

流星漫谈（二）

我们先来谈一谈流星界的“权威”机构——国际流星组织,英文简称为IMO。尽管IMO经常被各位作者提到,但读者对其的了解却大多只限于在它的官方网站http：／／www．imo．net上对“标准目视观测”的数据上报和流星雨流量的查看。其实IMO的内涵远不止此。说到“权威”,其实流星的研究和观测更多是爱好者的领地。多数观测者并非天文出身,     

中国古代流星记录的亮度归算

在中国古籍中关于流星“大如X”的纪录,是古人对星像视面大小的估测,此视面是人裸眼观星时由于光线的衍射、漫射以及视觉中的光渗作用造成的一种特殊感知现象．视面“大如X”的实质是亮度的记录．这些记录可以按古人目视观测天象的天球模型进行视大小(角直径)的量化,进而可以用一些已知亮度的流星记录为“标准点”,将其归算为亮度．并将古籍中流星“大如X”的4420次纪录的131种比体均作了亮度的归算．     

云南天文台对流星的视频观测

近20年来，随着CCD和像增强器的发展，小巧灵活的流星视频观测系统在世界上逐渐多了起来．并且，最终将可能逐步取代流星的目视观测和普通照相观测．介绍云南天文台I号流星彗星视频照相系统的研制及其初步观测结果．这一系统由容易转换的5组件构成．用于流星观测的大视场相机的视场约36度，单帧图像可观测到约6等恒星．实测的恒星星等测量精度可达约0.2等．还讨论了视频照相机比传统的感光胶卷照相的长处，以及视频照相系统的改进与发展．     

狮王怒吼“暴雨”如注

2001年天文学家的预测又一次牵动了众人的心,从专业天文工作者到业余爱好者,甚至普通百姓,都翘首企盼流星“暴雨”的到来。我们八位小组成员刚进入10月份就开始全面筹划,准备抓住近几年狮子座流星暴雨出现的最后机会。大家决定此次观测要分组进行目视观测和摄影记录。     

天文选址数字云量白天观测处理方法

云量观测是天文选址的重要考察项目.本文报告一种数字云量观测的处理方法,可以快速准确地计算选址点的云量值,避免了目视云量观测的人为误差.云量处理实验结果表明,该方法是合理可靠的, 在天文选址后期工作中能有效使用.该方法应用于西藏物玛观测点的云量观测统计,给出与同期目视云量的相关比较,并讨论数字云量处理的精度和改进方案.     

基于嵌入式人工智能设备的流星光学监测系统

流星光学监测网是定位陨石和观测火流星的基础科研设施. 流星光学监测系统利用光学相机高速采集天空图像, 使用嵌入式系统实时处理数据, 能够快速识别流星并获取流星位置和陨石落点信息, 是构成流星监测网的关键仪器. 为提高流星光学监测系统获取信息的实时性及准确性, 提出了一种基于嵌入式人工智能设备的流星光学监测系统. 该系统由软件及硬件部分组成: 硬件部分包括观测设备(商用高空抛物摄像头)以及数据处理设备(嵌入式人工智能设备); 软件部分运行于数据处理设备内, 主要包括控制界面模块、流星监测模块、数据管理模块. 实际工作时, 摄像头采集天空视频信息, 流星监测模块从视频流中实时监测流星并存储包含流星视频的数据, 数据管理模块将流星位置信息实时传回数据中心用于预警. 观测结束后, 将原始观测数据同步至数据中心用于后续科学研究. 在整个系统中, 流星监测模块决定了整个监测系统的实时性及准确性. 该系统采用嵌入式人工智能设备与人工智能算法结合的方法构建流星监测模块. 通过使用实测数据对搭载监测模块性能进行测试, 结果表明: 流星监测模块能够达到0.28%的低误检率以及100%的召回率, 且数据处理速度达到了Mobilenetv2的8倍. 进一步将包含监测模块的整个流星光学监测系统部署于太原理工大学-张壁古堡远程天文台, 通过实测表明流星光学监测系统实用中能达到100%的召回率和较低的误检率.     

冬夜迎狮王——北京天文同好会观测狮子座流星雨纪实

１９９８年狮子座流星雨期间,北京天文同好会有组织地进行了观测,取得了有价值的数据,并拍摄了大量的摄影作品。１１月２２日国际流星组织目视观测委员会主席给同好会发来贺信,感谢这来自中国的数据记录。同好会取得的成绩不断地得到专家和社会的肯定。     

我国古代记录的特殊流星现象与现代印证

中国古代有着大量的对于流星和流星雨的观测记录，最早可以追溯到3000多年以前。在这些珍贵的记录中，不仅有对于流星的一般描述，而且还有一些至今不能完全理解的特殊流星现象的记录。基于现代对电声变换流星声、流星体的螺旋线形运动、流星的颜色变化和流星的分裂等等的研究，列出在中国古代文献中可以查找到的有关记录。这些记录，不仅是世界文化宝库的一部分，而且对于今天的研究仍有实用价值。对电声变换流星声的报道，只是近20年来，才确立了的并非是观测者的臆想。流星的现代彩色照相观测，更真实地记录和展现了其他的特殊流星现象和它们的发生与演变。这些古代记录与现代的流星观测的对比，可以起到相互印证的作用。     

Acceleration of Numerical Integration of the Equations of Motion of Asteroids

Solar System Research - Finding and studying possible collisions of asteroids approaching the Earth requires a significant amount of computation. This paper describes the R0 program created to...     

A survey of orbits of co-orbitals of Mars

Many asteroids with a semimajor axis close to that of Mars have been discovered in the last several years. Potentially some of these could be in 1:1 resonance with Mars, much as are the classic Trojan asteroids with Jupiter, and its lesser-known horseshoe companions with Earth. In the 1990s, two Trojan companions of Mars, 5261 Eureka and 1998 VF₃₁, were discovered, librating about the L₅ Lagrange point, 60° behind Mars in its orbit. Although several other potential Mars Trojans have been identified, our orbital calculations show only one other known asteroid, 1999 UJ₇, to be a Trojan, associated with the L₄ Lagrange point, 60° ahead of Mars in its orbit. We further find that asteroid 36017 (1999 ND₄₃) is a horseshoe librator, alternating with periods of Trojan motion. This asteroid makes repeated close approaches to Earth and has a chaotic orbit whose behavior can be confidently predicted for less than 3000 years. We identify two objects, 2001 HW₁₅ and 2000 TG₂, within the resonant region capable of undergoing what we designate “circulation transition”, in which objects can pass between circulation outside the orbit of Mars and circulation inside it, or vice versa. The eccentricity of the orbit of Mars appears to play an important role in circulation transition and in horseshoe motion. Based on the orbits and on spectroscopic data, the Trojan asteroids of Mars may be primordial bodies, while some co-orbital bodies may be in a temporary state of motion.     

Graphical representation of periodic motion of the line of nodes of the Moon

In the text-books of astronomy, sections generally related to the Moon deal with the orbital elements of the Earth-Moon system such asa, e, i, , and the time of perigee passage. While the MEAN of the first of the three elements do not vary, mean longitude of the ascending node-mean longitude of the lunar perigee and the time of perigee passage undergoes secular as well as periodic changes due predominantly to the action of the Sun's gravitational attraction. While to a certain degree, explanations related to the calculation of the lunar orbit parameters are given, not a single graphical representation of these short- or long-periodic changes are presented. We allow the number of data related to these periodic changes must cover a large span of time; and if regression of the line of nodes or advances of the line of apses are to be graphically seen, data covering 18.61 and 8.85 yr, respectively, are needed. In this work we particularly aim at the graphical representation of the periodic changes of the line of nodes.     

Equation of state and anisotropy of pressure of magnetars

Magnetars are the neutron stars with the highest magnetic fields up to 10¹⁵–10¹⁶ G. It has been proposed that they are also responsible for a variety of extra-galactic phenomena, ranging from giant flares in nearby galaxies to fast radio bursts. Utilizing a relativistic mean field model and a variable magnetic field configuration, we investigate the effects of strong magnetic fields on the equation of state and anisotropy of pressure of magnetars. It is found that the mass and radius of low-mass magnetars are weakly enhanced under the action of the strong magnetic field, and the anisotropy of pressure can be ignored. Unlike other previous investigations, the magnetic field is unable to violate the mass limit of the neutron stars.     

Observations of the intensity of the penumbra of sunspots

Observations of the penumbral intensity of sunspots in 13 wavelength regions are presented. In 4 wavelength regions 54 sunspots are measured. In the other wavelength regions the number of sunspots considered ranges from 3–19.The penumbral intensity alters with position within the spot. This intensity variation is found to be comparable with the change in intensity from one spot to another. The penumbral intensity is found to be independent of spot size in the sample considered.The penumbra model of Kjeldseth Moe and Maltby (1969) with = 0.055 is supported by the measurements.