Movements of a Limb Flare and its Mass Ejection

A SN circular flare happened on solar southern-west limb on May 8,1989.There was an outstanding part in the center of the flare,and the part became later a cylindrical matter that ejected outside in the event.The movements of both the circular flare and the ejection of the cylindrical matter are analyzed and discussed respectively in this paper.An average expand velocity of the circular flare in diameter is measured to be 110 km·s^-1 in maximum,the expansion is so fast that it only takes 4 minutes that the diameter of the flare expands from the beginning to its maximum of 15500 km.But its diameter concentrates slowly,and the average shrinking velocity is about-20~-10 km · s^-1,it takes 17 minutes that the diameter reduces from the maximum to disappearance.For the ejected cylindrical matter,the expand velocity is 35 km·s^-1 on average,it takes about 7minutes that the diameter expands from the beginning to its maximum of 9060 km,but the shrinking process is 14 minutes,and the average velocity is^-15~-5 km·s^-1.The ejected velocity of the cylindrical matter still keeps high speed upward after the flare reaches its maximum,then the velocity begins to be smaller at three minutes after the flare maximum.The time in which the cylindrical ejected matter reaches the maximum height of 22000 km is same as that in which the diameter of the cylindrical matter expands to its maximum,the ejected matter ascending with an average velocity of 100~130 km·s^-1 and descending with an average velocity of-20~-5 km· s^-1,the matter ejected disappears gradually at the height about 16000~15000 km.