1989年8月17日耀斑后环系速度场分析

本文给出了１９８９ 年８ 月１７ 日耀斑后环的观测视向速度场，在环内物质在太阳重力、磁场梯度和大气压力梯度联合作用下沿环腿螺旋上升和环内物质密度由环腿向环顶和环足线性递增的假设下，理论上计算了该环系的视向速度场，理论计算和观测结果基本相符，似乎为耀斑物质由色球蒸发作上升运动的观点提供了间接的例证

AN ANALYSIS ON VELOCITY FIELD OF THE POST FLARE LOOP SYSTEM OF AUGUST 17, 1989

The line of sight velocity fields of the post flare loop system observed at Yunnan Observatory on August 17 in 1989 are given. A theoretical velocity field is computed under some assumptions that the matter within loop system up flows in helical lines from the loop feet to the top of the system under an united actions of solar gravity, both gradients of magnetic field and atmospoheric pressure, and the density distribution in the system increases linearly from the middle of the loops towards the top and the feet. The velocity field computed is basically similar to that observed. It shows that the assumptions mentioned above are acceptable. It seems to provide an indirect evidence for the evaporation model of solar flares.