一个中小型抛射的精细结构观测—太阳低层大气磁重联的证据

Fine Structure Observation of a Small- Mediate Mass Ejection

2000年6月18日中国科学院紫金山天文台赣榆观测站观测到太阳西边缘一个小型抛射现象,寿命仅15m.不属于耀斑的后期抛射现象,可看到十分精细的螺旋结构.用低层大气磁重联提供的初速约100km/s,在略去劳伦兹力情况下,给出了准均匀密度抛射柱所能达到的高度,和观测值一致.

A mediate-small ejection event with a lite-time lo mm. was observed at the west limb of the sun's disk using Ha -fine telescope at Ganyu station of Purple Mountain observatory, on June 18, 2000. It shows a nice fine structure of spiral form, quite different from the usual post-flare ejections. It could be explained as a phenomena of magnetic reconnection in solar lower atmosphere which presents an initial velocity of ~100km/s. Such an initial velocity leads to the observed height H ~20000 km of the quasi-homogeneous ejection cylinder under the assumption of a negligible Lorentz force.