火星的岁差和章动

火星是类地行星，火星动力学的研究不仅具有科学意义，而且还具有实际应用价值。火星的空间探测获得了许多有关火星极运动的重要资料，它与理论值的比较是检验火星内部结构的重要手段，也是为改进火星岁差章动理论提供依据的有效途径。介绍了当前国际上有关火星的岁差和章动研究的进展，分别对刚体火星的章动序列、火星内部结构参数化模型的建立和火星自转的简正模作了描述，并进行了简单的讨论。     

火星指向模型与重力场模型的发展回顾与使用

首先回顾了火星重力场模型的发展历程;然后介绍了火星重力场模型使用中涉及的坐标系统,并给出了各坐标系之间的相互转换关系,再比较了基于不同火星指向参数模型进行坐标转换的差异;最后从重力异常与星历积分两个方面对最新的火星重力场模型GMM-3与JGMRO 120d进行了比较,结果表明两个重力场模型在精度上较为一致,对于10 m量级精度的定轨要求,模型的选取无特殊要求。     

探秘火星(三)

Q1哪个探测器将深入到火星地下探测?几十年来,人类一直对火星进行探索,之前登陆火星的探测器,如勇气号、机遇号、好奇号等,都是探测火星表面上的火山、峡谷、岩石、土壤的演变历史。只探测地表特征,是无法了解火星早期的演化情况的,因为包含此种信息的样品都深埋于火星地表之下。     

深空探测天文自主导航技术综述

自主导航技术在提高深空探测器自主生存能力、减轻地面测控负担、完成探测任务特殊阶段导航等多方面具有明显的优势,已经成为世界各国研究的热点。我国火星探测工程已经启动,将来还有其他小行星、彗星和行星及其卫星的探测计划。详细阐述了发展天文自主导航技术的必要性,阐述天文导航技术的基本原理及优势,并对国内外深空天文自主导航技术以及应用情况进行概述,总结了发展天文自主导航的关键技术。根据分析提出我国发展深空探测自主导航技术的建议与思考。     

2011年世界空间探测与科学观测活动回顾

2011年,美国、中国和俄罗斯等国都开展了多项空间探测与科学观测活动,发射了月球探测器、木星探测器等,尤其是由于2011年有火星探测器发射窗口,所以进行了两次重要的火星探测器发射,但有喜有悲：携带了世界最先进火星车“好奇号”的美国“火星科学实验室”顺利升空,并奔向火星;而携带了中国首个火星探测器“萤火-1”的俄罗斯的“火卫一-土壤”探测器虽然发射成功,但由于探测器本身故障而无法进入地火转移轨道,导致该任务失败。     

宁静日冕和冕洞研究现状

主要论述宁静日冕洞，以及日冕加热问题的研究现状。讨论了宁静日冕的理论模型、观测模型和混合模型，以及冕洞区大气模型和太阳风加热问题。最后对计划中的日冕空间探测作了简要介绍。     

雷达对火星次表层的探测与研究现状

大量火星地貌及表面物质成分的研究表明火星上曾经存在地表水,而目前已探测到的火星上的水广泛存在于极区冰盖和次表层中。近十二年来,欧洲火星快车上搭载的火星次表层和电离层探测先进雷达和美国的火星勘测轨道器上搭载的浅表雷达已经开展了对火星次表层的探测和研究,并取得了一系列科学成果。火星次表层记录着火星形成与演化的重要历史信息。对火星次表层的探测和研究,可以为了解火星的物理特性和构造组成,探寻火星生命,研究火星的地质演化历史提供科学依据。综述目前利用雷达对火星次表层进行的探测和研究,介绍了雷达探测的原理与方法,总结了已取得的科学成果,并展望未来的火星探测雷达。     

火星探测成果丰硕

火星探测成果丰硕本利去年第５期曾经载文介绍过火星环球勘测者和火星探路者的基本情况,第６期又对火星探路者的一些探测成果做了报道。在这一期里,本刊又拿出了封面、封底和封二如此大量的篇幅继续介绍火星探测新成果。做为本刊的编辑,我陆陆续续看到了火星探路者和环...     

飞行器近小行星轨道动力学的特点及研究意义

该文在介绍小行星及对其探测意义的基础上,以NEAR、Muses-C(Hayabusa)小行星探测器为例,重点分析了飞行器与小行星距离较近时(near asteroid)的动力学环境及其对环绕小行星飞行的飞行器设计的影响.并以旋转的二阶二次重力场和小行星Castalia为例,进一步阐述近小行星轨道动力学的一些特点和结论.此外,还给出了小行星探测的一些建议和设想.     

再见,机遇号

2002年,美国“双胞胎”火星探测器出生了,它们被分别赋予了"勇气号"与"机遇号"的名字。为了寻找火星上可能出现的水,2003年6月10日与7月7日,勇气号与机遇号两姐妹从家乡地球岀发,并分别于2004年1月4日、1月25日安全着陆于火星的两面,承担着人类的使命,开始对这颗红色的星球进行探测。     

"日中乌"辨析

从观测资料可认证史载“日中乌”是指太阳黑子,而“阳乌载日”则是日全食时的日冕。二者并非神话,而是写实文字。     

SiS in Orion-KL: evidence for "outflow" chemistry

SiS has been conclusively detected toward Orion-KL via its J = 6-5 and J = 5-4 rotational transitions at 91 and 109 GHz. Line profiles indicate that the species is present at an LSR velocity of 7.5 km s-1 with a half-width at zero power of 36 km s-1. Such characteristics associate SiS with the moderate velocity outflow (V approximately 18 km s-1) centered on IRc2 and observed in thermal SiO, the NH3 "plateau," and OH, H2O, and SiO masers. The column density estimated for SiS in this region is Ntot = 4 x 10(15) cm-2, corresponding to a fractional abundance of f approximately 4 x 10(-9). Such an abundance implies an SiO/SiS ratio of approximately 60 in the outflow material, remarkably close to the cosmic O/S ratio of approximately 40 and contrasting with the SiO/SiS value of > approximately 10(3) predicted by ion-molecule models. This difference is probably a result of the high temperatures and densities present in the outflow, which favor thermal equilibrium abundances similar to those observed in the circumstellar shells of late-type stars rather than "ion-molecule"-type concentrations. In addition to SiS, some twenty new unidentified lines near 91 and 109 GHz were detected toward KL, as well as transitions arising from HC5N, HC13CCN, HCC13CN, O13CS, and, possibly, CH3CH2OH, CH3CHO, and CH3OD.     

“Small Equipment Strategy” in the Development of Astronomy

Astronomy is an observational science. This paper points out that in the development of astronomy, the means of observation at every stage has as its main body the large equipment of the time, but equally important is the simultaneous development of small equipment as strategic complement. A number of historical examples are cited. The recently suggested“Special Radio Telescope Dedicated to Pulsar Research” originates in the small equipment strategy, and a brief introduction to this instrument is included here.     

Force-free magnetic fields may have a "loss of equilibrium"

By comparing the light curves in optical, hard x-ray, and soft x-ray wavelengths for 8 well-observed flares, we confirm previous results indicating that the white light flare (WLF) is associated with the flare impulsive phase. The WLF emission peaks within secondsafter the associated hard x-ray peak, and nearly two minutesbefore the 1–8 soft x-ray peak. It is further shown that the peak power in nonthermal electrons above 50 keV is typically an order of magnitudelarger, and the power in 1–8 soft x-rays radiated over 2 strdn at the time of the WLF peak is an order of magnitudesmaller, than the peak WLF power.Operated by the Association of Universities for Research in Astronomy, Inc., under cooperative agreement with the National Science Foundation. Partial support for the National Solar Observation is provided by the USAF under a Memorandum of Undestanding with the NSF.     

"陶寺观象台"发掘与古代文献的印证

古代文献记载帝尧时的历法存在两种不同说法。羲和观测四仲中星定季节当是不实之辞,并以闰月成岁推论为使用农历也没依据。羲和观测太阳出没方位变化而"生十日"、即制订产生十月太阳历才符合事实。在文[1]中的推论,也与后一种说法可互相印证。本文对文[1]的推论作出了论据补充,与文[1]成姐妹篇。     

The Mass Function of Young Star Clusters in the "Antennae" Galaxies

We determine the mass function of young star clusters in the merging galaxies known as the "Antennae" (NGC 4038/9) from deep images taken with the Wide Field Planetary Camera 2 on the refurbished Hubble Space Telescope. This is accomplished by means of reddening-free parameters and a comparison with stellar population synthesis tracks to estimate the intrinsic luminosity and age, and hence the mass, of each cluster. We find that the mass function of the young star clusters (with ages less, similar160 Myr) is well represented by a power law of the form psi&parl0;M&parr0;~M-2 over the range 104 less, similarM less, similar106 M middle dot in circle. This result may have important implications for our understanding of the origin of globular clusters during the early phases of galactic evolution.     

关于"长河二号"导航系统的时间同步及授时

对“长河二号“导航系统的时间同步及快速恢复等问题作了讨论,提出了利用BPL长波信号、GPS共视或搬运钟等方法来实现时间同步和增加授时功能的方案.最后,给出了“长河二号“东海台链的主台信号与国家授时中心的UTC(NTSC)之间的同步实验结果.     

"水平式"施密特(Schmidt)望远镜光学系统的调整方法与步骤

近年来我们为青海德令哈观测站安装了一台施密特(Schmidt)望远镜,还把云南天文台原德制施密特望远镜机架进行了设计、改装成"水平装置".它们的改正镜口径约为Φ400mm,焦距约为800mm,用于观测人造卫星及空间碎片,用CCD作为接收器,提高了工作效率,为神州发射提供了资料.本文所述的是对这两台施密特望远镜光学系统的调整方法与步骤.     

An Ancient Solar Eclipse Record “Tian-da-yi“ in the 10th Century BC

The ancient record“Tian-da-yi“(the sky darkened greatly )is identified with the solar eclipse on May 31,976BC.This identification is demonstrated in this paper through a palaeographic ,astronomical and chronological analysis,It is probably the earliest solar eclipse in Chinese histroy that can be so identified.     

脉冲星“晃荡”所产生的引力辐射

本文得出了含有自引力、内应力和内部运动项的脉冲星“晃荡”的多极引力辐射公式,并用该公式估算了脉冲星Crab和Vela的引力辐射功率,最后讨论了该公式的理论意义。