海尔-波普彗星离子尾的间断和波动

The Disconnection and Rippling of the Ion Tall of Comet Hale-Bopp

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。观测时刻的子尾内物质运动速度约为 5 0km/s ;离子尾线向主尾主轴的并拢速度约为 0 .0 80′/s。 1997年 3月 3日海尔 -波普彗星离子尾有波现象发生。波动发生在距离彗星密度中心约 130× 10 4 km ,偏离主轴 30°处。振幅约 2 0× 10 4 km、其离子束宽度约8× 10 4 km、波动的相速度约为 2 0 0km/s。

The observations on large scale structure of Comet Hale-Bopp made around perihelion at Purple Mountain Observatory lead to the following results: 1) A disconnection event has been taken place on Feb.16, 17 and 18 in 1997. From these images it is obtained that the moving velocity of matter within the ion tail is about 50km/sec and the closing speed of a ray toward the main tail axis is 0′.080/sec during the corresponding period of observation. 2) There is a rippling appeared in a beam of ion tail on March 3,1997. Its phase velocity is about 200km/sec and its amplitude is about 0.2 million km. The width of this ion beam is 0.08 million km. The relevant data are obtained by means of PDS measurement.