【摘要】 利用紫金山天文台里奥型色球Hα(6562.8A)望远镜,其滤光器带宽为0.75A,太阳像直径为15.2mm,附加一组透镜使像放大至10cm,获得了1981年4月27日日面西边缘大爆发环状日珥事件的Hα资料(0816—0951UT)(见附图22)。 这次环状爆珥事件很可能是MW22216群(SESC3049)(15N,150L)在0720UT的X5.5级大爆发事件后的耀斑环。观测资料表明: 1.环形结构早于0816UT。环足部有耀斑状亮块。 2.0816-0826.5UT;0830-0837UT;0839-0908UT时环北支(B支)较南支(A支)粗。而0828.5-0830UT;0837.5-0838.5UT时A支较B支粗。 3.在0829.5UT和0833UT时,环顶部分别出现奇特的结构,持续均约1分钟。 4.在0836.5UT时,环顶出现小针状突出物,并逐渐上升,变粗;0839UT环顶小突起结构达最大高度。0847UT环顶出现新的突出结构,它逐渐弯向B支。0853UT时可见B支的扭转结构。 5.A足点随环珥上升而逐渐向南(向外侧)移动,B足点变化较小。0855UT前后,A足点外移加快,环珥变化明显:环足部明显分开,高度明显增加,环顶管经略降后陡增。 6.测量表明,0844UT前环珥几乎以 8.4km/sec匀速上升。环顶管径由0816UT时的0.74×10~4km迅速增至0826UT时的1.27×10~4km,此后至0855UT环顶管径变化不大。在0844—0853UT环珥以-0.012km/sec~2的平均加速度上升。在0853UT环再上更多还原

【Abstract】 We observed a great eruptive loop-prominence on the solar western limb during 0816-0951UT on April 27, 1981, using our Lyot type Ha (6562.8 A) chromosphric telescope. The telescope has the objective with the diameter of 14cm and focal distance of 140cm, and the passband of filter is 0.75A, the diameter of solar image is 15.2mm. We added a set of lens to the telescops in order to amplify the solar image to 10cm.After the great x-ray burst (Class X5.5) occurred at 0720 UT, we observed a post-flare loop. Its location was about Φ=15N, λ =150L (MW No:22216 group or SESC No:3049). Our observational results are as followS:1. The loop-like structure appeared before 0816UT, the flare-like bright patch appeared in the outsides of the foot points.2. In the period of 0816-0826.5,0830-0837 and 0839-0908, the northern leg (Leg B) of the loop was thicker than the southern leg (Leg A), and during 0828.5-0830 and 0837.5-0838.5 the leg A was thicker than the leg B.3. The strange structure appeared at the top of the loop at 0829.5 and 0833, which lasted for about one minute.4. A protuberant thing in the shape of a spicule appeared at the loop top at 0836.5, rising and thickening gradually and reached the maximum hight at 0839. A new protbuerant structure appeared once again at the loop top at 0847, which gradually bended itself toward the leg B. We could see the twist structure in the leg B at 0853.5. The foot point A rised and moved gradually towards the south (towards the outside) while the foot point B changed slightly. At about 0855, the foot point A moved more rapidly and the loop-prominence changed obviously: the feet of the loop separated apparently and the hight of the loop also increased apparently while the diameter of the tube of loop at the top decreased slightly at first and then increased steeply.6. On the basis of our measurement, before 0844, the loop-prominence almost riscd at the constant velocity of 8.4 km/sec. The diameter of the tube of the loop at the Lop increased rapidly from 0.74×l04 km at 0816 to 1.27×104 km at 0826. But at 0855 the diameter of the tube at the loop top changed slightly. The loop-prominence rised with the average acceleration of -0.012 km/sec2 during 0844-0853, and its ascending velocity decreased down, to 1,8 km/sec at 0853,更多还原