一次哈雷彗星爆发现象的观测和分析

哈雷彗星于1986年3月21日到26日期间,经历了一次非正常光变,产生了爆发.本文对用窄波段光电光度观测到的爆发过程中各波段所发生的基本物理机制和化学反应过程进行了分析和讨论.      

木星伽利略卫星互掩互食天象的测光技术

对行星天然卫星互掩互食天象进行测光可以得到非常准确的天体测量信息, 这些信息可以用来进一步改进行卫星的运动理论和历表. 对2003年在云南天文台1米望远镜上实际观测到的互掩互食图像进行测光处理, 分析表明, 在对木星去晕和测光孔径为1.5~2.0倍半高全宽条件下, 所得光变曲线有较好的稳定性.      

挖掘“脏雪球”内部的秘密

近年来,人类对彗星越来越感兴趣,2004年1月2日,飞行已久的美国星尘号彗星探测器与怀尔德2号彗星交会。2004年3月2日欧空局发射了第1个彗星探测器“罗塞塔”。它将经过10年的长途跋涉进入楚留莫夫-格拉西门克彗星轨道,并向该彗星释放着陆器。现在美国人又把“深入撞击”彗星探测器送上太空,为的是“上演”惊心动魄的太空大撞击。那么,如此频繁的发射彗星探测器,究竟是为了什么呢?彗星曾被人描述为“脏雪球”。它生成于比海王星轨道还要远的、环绕太阳运行的一个由神秘天体构成的带,是由太阳系诞生初期的物质构成的。由于它自身的温度极低并处…     

NASA总结Spitzer在轨15年的重要科学发现

正Sciencealert网站2018年9月21日报道,NASA最新系外行星观测任务凌日系外行星勘测卫星(TESS)已经可以提供有价值的数据,发现和研究新的系外行星。2018年4月18日TESS任务发射升空;7月25日TESS进行了首次测试观测并成功观测到一颗彗星;8月7日TESS开始首次正式科学观测;TESS正式运行2个月发现两颗候选系外行星。     

海尔-波普彗星离子尾的间断和波动

给出海尔-波普彗星近日点附近大尺度观测的结果.指出:1997年2月16、17和18日海尔-波普彗星等离子尾部分有断尾事件发生.观测时刻的离子尾内物质运动速度约为50km／s;离子尾射线向主尾主轴的并拢速度约为0.080'／s.1997年3月3日海尔-波普彗星离子尾有波动现象发生.波动发生在距离彗星密度中心约130×104km,偏离主轴30°处,振幅约20×104km、其离子束宽度约8×104km、波动的相速度约为200km／s.      

Rosetta对Aswan悬崖崩塌的观测揭示彗星原始冰冻内部

<正>ESA网站2017年3月21日报道,罗塞塔(Ro-setta)彗星探测器任务科学家首次确定彗星67P发生的一次突然、短暂的爆发与悬崖崩塌相关,这一发现有助于了解此类事件背后的驱动力,研究论文发表在Nature Astronomy上。Rosetta于2014年9月近距离拍摄的彗星图片显示,名为Aswan的突出的悬崖边有一道长约70m、宽约1m的裂缝。此后,随着彗星67P越来越飞近其近日点,彗星上掩埋的冰气化并裹挟尘埃散入空间     

“深入撞击”彗星探测器发射升空

2005年1月12日,举世注目的“深入撞击”彗星探测器在德尔它2火箭的托举下,从卡纳维拉尔角空军基地发射升空。这一价值3.3亿美元的彗星探测器,将在飞行4.31亿千米之后,于2005年7月4日,撞击“腾佩尔”彗星,以研究彗星内部的秘密。该项目主要负责人赫恩教授认为:“从太阳系形成至今,只有彗星的内部物质是一直没有变化的。在这之前,我们并不了解彗星内部的情况,因此我们希望通过这次‘深入撞击’来收集彗星内部的信息。”此举是人类第一个实际接触并探索彗星的空间计划。俄罗斯发射白杨导弹2004年12月24日,俄罗斯战略导弹部队从普列谢茨克航天发…     

“质子”号发射俄通信卫星

<正>3月19日,俄罗斯"质子"M/"和风"M型运载火箭在拜科努尔发射场发射了俄罗斯卫星通信公司的"快讯"AM7通信卫星。"快讯"AM7由空客防务与航天公司采用"欧星"3000平台建造,发射质量5712千克,配备24路C波段、36路Ku波段和2路L     

空间扫描

欧空局于７月１日展示“罗塞塔”彗星探测器模型　它将在２０１２年与“维尔塔宁”彗星会合。欧洲在彗星探索方面已居于领先地位，１９８６年曾成功把“乔托”探测器发射到了距离“哈雷”彗星不到６００ｋｍ远的地方。与“乔托”不同的是，“罗塞塔”在２０１２年５月２８日与“维尔塔宁”彗星会合之后，将沿距彗星表面仅１ｋｍ的轨道环绕彗星飞行，而不仅是擦肩而过。它还将向彗星扔下一个１００ｋｇ重的着陆器，着陆器再发射一把带倒钩的叉子，使之插入彗星，以确保探测器不会因为碰撞而弹离彗星。日本Ｈ－２Ａ火箭开发受阻　１９９９年３…     

日本第14号科学卫星

日本文部省宇宙科学研究所于1991年8月30日从鹿儿岛宇宙空间观测所用M-3SⅡ(第6枚)火箭发射第14号科学卫星(SOLAR-A)。 SOLAR-A是观测太阳耀斑时释出的X射线和γ射线的观测卫星,是继1981年2月发射的第7号科学卫星(天文卫星-1)之后,日本的第二颗太阳物理观测卫星。众所周知,太阳活动周期为11年,太阳在活动最盛期在其表面频繁出现爆发现象,爆发时间短的只有数十秒,长的可达数小时,这时产生X     

Cometary kilometric radio waves and plasma waves correlated with ion pick-up effect at comet Halley

From the discrete spectra of the emissions from the comet in the frequency range from 30 to 195 kHz named CKR (Cometary Kilometric Radiation), movements of the bow shock at comet Halley are concluded, i.e., the observed CKR emissions can be interpreted as being generated and propagating from the moving shock. The motion of the shocks are possibly associated with time variation of the solar wind and of the cometary outgassings. By in-situ plasma waves observations using PWP (Plasma Wave Probe) onboard the Sakigake spacecraft, the characteristic spectra of the electrostatic electron plasma waves, the electron cyclotron harmonic waves, and the ion sound waves have been detected during the interval of the Halley's comet fly-by. Compared with the results of a Faraday cup observation and a magnetometer, it is concluded that these plasma wave phenomena are the manifestation of the ion pick-up processes. The ion pick-up processes are taking place even in the remote region within a distance range from 7×10⁶ to 10⁷ km from the cometary nucleus.     

Search for organic molecules in the outer solar system

Recent developments of millimeter astronomy have led to the discovery of more and more complex molecules in the interstellar medium. In a similar way, attempts have been made to detect complex molecules in the atmospheres of the most primitive bodies of the Solar System, i.e. outer planets and comets, as well as in Titan's atmosphere. An important progress has been achieved thanks to the continuous development of infrared astronomy, from the ground and from space vehicles. In particular, an important contribution has come from the IRIS-Voyager infrared spectrometer with the detection of prebiotic molecules on Titan, and some complex organic molecules on Jupiter and Saturn. Another important result has been the observation of carbonaceous material in the immediate surroundings of Comet Halley's nucleus. In the near future, the search for organic molecules in the outer Solar System should benefit from the developments of large millimeter antennae, and in the next decade, from the operation of infrared Earth-orbiting spacecrafts (ISO, SIRTF).     

Recent infrared observations of comets with UKIRT and IRAS

A preliminary analysis of infrared observations of comets P/Crommelin and P/Tempel 1 is presented. Comet P/Crommelin was observed from UKIRT over the range 1–20 micron, using standard filters. From the shape of the thermal emission spectrum, the temperature of the dust grains is estimated (T = 314 ± ₃₃⁴⁴K) and also the dust production rate (1.3 × 10⁵gs^?1). Comet P/Tempel 1 was observed with the Infrared Astronomical Satellite (IRAS). The emission is found to be considerably extended and there is also evidence for temperature variation of the dust grains as indicated by the 12 to 25 micron flux ratio.     

地球磁暴(1910.5.18)与哈雷Ⅰ型彗尾(1910 Ⅱ)的联系

本文探讨1910年5月18日菉葭浜天文台所记录的一次地球磁暴的暴源;解释哈雷彗星凌日与磁暴开始时刻之差;分析哈雷I型彗尾的某些特征并讨论磁暴机制.      

Hydrogen coma of comet P/Halley

The main molecular processes to produce the hydrogen comae of comets are now well known: Water, the main constituent of cometary atmospheres, is photodissociated by the solar ultraviolet radiation to form the high (20 km s⁻¹) and low (8 km s⁻¹) velocity components of the atomic hydrogen. The hydrogen clouds of various fresh comets have been observed in 1216Å by a number of spacecrafts. Ultraviolet observations of short period comets are, however, rather rare. Consequently Comet P/Halley in this apparition is a good object to obtain new physics of the hydrogen coma. Strong breathing of the hydrogen coma of this comet found by “Suisei” provides just such an example. The rotational period of Comet Halley's nucleus, its activity in the form of outbursts alone, and the position of jet sources etc. are determined from the breathing phenomena. Atomic hydrogen from organic compounds with a velocity of 11 km s⁻¹ play an important role in that analysis. The time variations of the water production rate of Comet Halley during this apparition observed by various spacecrafts appear to be in agreement with each other and are about 1.5–2 times larger than the standard model. The difficulty of the calibration problem was emphasized.     

Vega project — Three channel spectrophotometer for the Halley''s comet investigation

A spectrometer for the Halley's Comet Investigation after the VEGA Project is described in the present work. It consists of a telescope and three spectral channels: UV (120 – 290 nm), resolution Δ λ / λ = 170; VIS (280 – 710 nm), resolution Δ λ / λ = 170; IR (950 – 1900 nm), resolution Δ λ / λ = 70.

With the help of two-coordinate scanner, the secondary mirror of the telescope allows spatial scanning of the Comet with a frame 2°×1,5° with 105 different pixels.     

Simultaneous measurements of sea surface temperature by GMS-1 and GMS-2

For accurate measurements of sea surface temperature in the 11 μm window region, it is necessary to eliminate the effect of atmospheric absorption. A technique using observations from different angles is one of the methods of eliminating this atmospheric effect. This technique is not possible at present, using a single satellite; but using two geosynchronous satellites, it is possible to observe a common area from two different elevation angles. To correct for atmospheric effects, therefore, we compared the infrared data obtained from observations at about the same time (less than a minute apart) on the equator using the GMS-1 and GMS-2 satellites which had about 20° longitudinal separation. It was found that if the infrared spectral wavelength channel of one geosynchronous satellite is selected to be different from that of the other, it is possible to improve the two-satellite observation technique of estimating water vapor content in a tropical atmosphere. This technique corresponds to split window measurements by the AVHRR radiometer on board the NOAA-7 satellite.     

The Comet Halley flyby I.R. sounder “I.K.S.”

An infrared sounder is being developed in France to observe in 1986 Comet Halley from the Soviet “VEGA” flyby probes. The instrument, called “I.K.S.”, has three measuring channels. Two of these channels will provide the spectrum of the comet emission in the spectral intervals 2.5–5.0 μ and 6–12 μ, at a constant resolution λ/Δλ = 50.The third channel analyzes the comet I.R. image at a spatial frequency of about 1 arc minute^?1; two I.R. colours are used in this channel: 7–10 μ and 10–14 μ. From the results expected, it is hoped that (1) most primary simple molecules emitted by the nucleus will be identified; (2) the chemical composition and perhaps crystalline structure of the dust grains and ices released by the comet will be derived; and (3) the diameter of the nucleus and its brightness temperatures will be measured.     

中国山西地区法布里-珀罗干涉仪测风能力及数据质量检验

介绍了中国气象局山西岢岚大气观测站(39°N, 112°E) 法 布里-珀罗干涉仪(FPI) 的基本 构造、测风能力、程序处理流程、数据质量控制方法以及检验情况. 岢 岚观测站FPI可以观测892.0 (OH)nm, 557.7 (OI)nm和630.0 (OI)nm 波 长处气辉谱线的多普勒移动, 分别计算对应87km, 97km和250km高度处 的大气风速和大气温度, 可给出中间层顶区域及热层风的大气潮汐和扰动 情况. 采用水平风模型(HWM)输出结果进行交叉检验, 对FPI测风数据质量进行验证. 结果显示, 岢岚大气观测站FPI仪器的测风数据 在长期趋势上与HWM模式的输出数据一致, 风速变化幅度有季节性差异, 数据质 量控制方法有效, 测风误差在87km高度处为5.7m·s-1, 97km处 为1.3m·s-1, 250km处为4.1m·s-1, 测风数据 通过了可靠性检验.      

基于VO_x非致冷探测器的红外地球敏感器探讨

近年来VOx非致冷红外探测器的研制取得了较快发展,由于在波长14~16μm范围内有较高的响应率,使其应用于红外地球敏感器成为可能.介绍了基于VOx非致冷红外探测器的红外地球敏感器,对主流VOx探测器的MEMS微桥结构和产品性能参数进行比较,并分别讨论了使用面阵器件和线阵器件的红外地球敏感器应用.