1.56m望远镜观测彗—木相撞概况

用上海天文台佘山观测站的１．５６ｍ望远镜和ＣＣＤ照相机，观测到彗－木碰撞的六次事件。本文给出由撞击引起的木卫闪光Ｋ＝１２的光变曲线和一些碰撞后木星的照片。     

彗木相撞中的波动

1994年7月18日至24日期间，彗星苏梅克-列维9(SL-9)的超过20块碎片与木星发生了相撞．哈勃空间望远镜(HST)拍摄到的图像揭示了木星大气对撞击的动力学响应．具有重要意义的是观测到5个撞击点周围的圆环，它们以450米／秒的常速度向外运动．环的圆形性表明它们是波．因为对于不同大小的撞击，波速是常量，可以推断出传播速度与爆炸能量无关．这意味着这些波动是线性波．评述现行理论所使用的3类候选波，亦即惯性引力波、声波和地震波，介绍的重点是前面两种．     

1994年7月17日至22日“彗木相撞”的白光照相观测

1994年7月17日至22日“彗木相撞”期间,在紫金山天文台进行了木星胶卷照相观测。木星胶卷像是用赤道仪20公分的折光望远镜加上拍摄太阳黑子放大像的照相装置获得的,木星胶卷像的直径约4.5毫米。“彗木相撞”后的木星胶卷像上留有明显的“大黑斑”创面。     

彗木碰撞期间3.6和12cm射电观测

本介绍了１９９４年７月ＳＬ－９彗星撞击木星期间３．６ｃｍ和１２ｃｍ射电连续谱观测的结果。在３．６ｃｍ波长上，撞击事件无明显的视效应，在１２ｃｍ波长上，木星的射电平均视流量增加约２０％。     

由彗木碰撞引起的十米波爆发

据中国科学院北京天文台与电子工业部２２所的联合观测，证认出１９９４年７月２１日的木星十米波爆发中，有一个爆发可能是由于彗星木星碰撞引起的。     

彗木两次碰撞过程分析

Ｓｈｏｅｍａｋｅｒ－Ｌｅｖｙ９号彗星与木星碰撞，是人类有史以来第一次有预报的天体大碰撞。有关观测的初步结果，秀快通过新闻报道和电子网络传遍了全世界。本文通过对其１４号、１１号核撞击木星的大量报道的综合分析，对彗木碰掸的物理过程、彗木碰撞时刻的确定等重要问题进行了探讨。     

彗木相撞中的惯性引力波

苏梅克-列维9号彗星(SL9)与木星相撞后，在木星上观测到的以常速度(～450m／s)向外扩展的圆环意味着这是碰撞在木星大气中引起的线性波动．我们选取：非旋转、无粘性、密度分层、不可压缩的木星大气模型，而且木星大气以水平速度U=b az运动；给出初始扰动压力P(r；0)作为碰撞的初始条件，用流体力学方程组求解了彗木相撞中的惯性引力波．结果表明：当木星大气以速度U=U0(～170m／s)运动时，彗星碎片的大部分能量都用来产生内波，同时还得到彗星碎片的撞击深度H与水平相速Vp的关系式．当木星大气以速度为U=b az运动时，木星大气的扰动能量不再是在动能和势能间均分。     

彗木相撞的不可压缩分层流体模型

提出了一个彗木相撞的线性模型．在这个模型中，将木星大气看作是一个分层的、不可压缩和无粘滞的流体层，而与撞击相联的引力波则由一个初始冲力所造成．采用初始冲压P(r，z，0)代替初始表面形变作为初始条件．发现这种做法使得问题的数学处理更加方便，特别是在计算流体粒子的垂直位移和摄动势能方面，后者可以表为P(r，z，0)的有限傅立叶正弦和余弦变换．导出了一个联系彗星碰撞参数、木星大气参数和所设初始冲力之间的关系式．还对两种P(r，z，0)的假设形式分析地导出表面波波高．     

由彗木碰撞引起的十米波爆发

据中国科学院北京天文台与电子工业部２２所的联合观测，证认出１９９４年７月２１日的木星十米波爆发中，有一个爆发可能是由于彗星木星碰撞引起的。     

苏梅克－利维9号彗星撞击木星事件的光学观测

本文给出了１９９４年７月１７日至２２日，彗星碰撞期间，福州和乌鲁木齐两个观测点所取得的部分光学观测资料。     

SL9彗星撞击木星时S碎片的CCD观测

用上海天文台１．５６ｍ望远镜和ＣＣＤ照相机，观测ｓ＝５碎片时，发现了类似彗尾的奇异现象。     

我国对苏梅克-列维9号慧星撞击木星事件的观测(英)

1994年7月16日─22日，苏梅克－列维9号周期慧星的21颗碎片连续撞击木星事件是一次极为罕见的天文现象．文中概括介绍了我国天文学家对慧木相撞事件的光学和射电观测网点、课题设置以及所取得的主要观测结果．     

Sodium emission from Comet Shoemaker-Levy 9 in the magnetosphere of Jupiter

On July 20, 1994, before the Q fragments of Comet Shoemaker-Levy 9 fell to Jupiter, more than 200 spectra of the Jovian features were obtained at the Crimean Astrophysical Observatory in the wavelength range 5700–7600 Å with a 26 s exposure time and a spectral resolution of 20 Å. We found a time-varying Na D line emission in the form of two components with Doppler shifts of about 30 Å. The brightest and most frequent sodium flares were detected when the Q fragments passed through the Jovian inner magnetosphere at a distance of about three the Jovian radii (3R_J) from its center, where they crossed the Io-Jupiter current tube. A frequency analysis of our data revealed a flare recurrence time scale of 1 min. We conclude that sodium was released from the cometary dust and from the surfaces of numerous cometary debris and that its amount was enough to produce the observed emission. The observed high-speed clouds of sodium atoms are assumed to have been formed through ionization, ion acceleration by the bidirectional electric fields of Alfvén waves in the Io-Jupiter current tube, and their neutralization.     

The impact of comet SL9 with Jupiter: IR observations at TIRGO

Infrared images of Jupiter have been obtained on 5 nights before, during and shortly after the period of the impacts of the fragments of comet Shoemaker-Levy 9 (1993e) with the giant planet. Long lived bright spots produced by the impacts have been measured and analyzed. By measuring the intensity variation of the spots as a function of Jupiter rotation we show that these spots are likely constituted by large and thin clouds of dust located above the methane layer. The IR relative albedos has been also measured for some of these spots.On leave from Center for Astrophysics - Cambridge (USA)     

SL9彗星碎块穿入木星大气的深度

ＳＬ９慧星撞击木星类似于大气中陨落的流星现象，是替星与木星大气相互作用的过程．慧星碎块的质量取为１０（１２）、１０（１３）和１０（１４）ｋｇ，其密度分别为３．０、１．０、０．８、０．５和０．２ｇ／ｃｍ３．结果表明：这些慧星碎块能穿透木星大气的氨云层，在接近１ｂａｒ的地方爆炸，这与文［１］的模拟结果一致．     

Flux monitoring at 327 MHz during SL9-Jupiter collision

Jupiter flux at 327 MHz was monitored using the Ooty radio telescope from July 12th to July 29th during the collision of comet Shoemaker-Levi 9 with Jupiter. Flux was found to increase steadily from July 17th to July 26th by ∼ 2–5 Jy, after which it declined to its pre-event value. The comparison of 327 MHz observations with those at 840 MHz and 2240 MHz indicates that the enhancement was mainly due to the increased synchrotron emission and the contribution of thermal emission was very small at metric-decimetric frequencies. The enhancement in radio emission was found to be more at 840 MHz than at 327 or 2240 MHz. The steepening of the spectrum between 327 and 840 MHz as well as between 2240 and 840 MHz was also noted.     

3.6/12 cm radio observation of Jupiter during the impact by Comet SL-9

We present 3.6/12 cm dual-frequency radio continuum observations of Jupiter with the Shanghai Observatory 25 m radio telescope during the impact by comet SL-9. There was no appreciable variation in the daily average flux density at 3.6 cm wavelength, but a relative increase of about 20% at 12 cm was observed during the impact.     

彗木碰撞期间3.6和12cm射电观测

本文介绍了1994年7月SL－9彗星撞击木星期间3．6cm和12cm射电连续谱观测的结果．在3．6cm波长上，撞击事件无明显的视效应，在12cm波长上，木星的射电平均视流量增加约20％．