【摘要】 1989年1月14日AR5312（怀柔编号89009）活动区,产生了一个2B级耀斑。该活动区经纬度为L306、S32,黑子群磁场分类为δ型。耀斑开始时间为0202UT,结束为0534UT,持续了3个多小时。北京天文台磁场望远镜,得到了一系列较完整的高分辨磁场及速度场资料,包括光球5324A的矢量磁场图和色球4861A的纵向磁场图（图1、2）。从耀斑前后的磁图得到以下结果: 1、耀斑初始亮点位于纵向磁场中性线附近高度剪切区域（见图1B区）、新浮磁流区（图2D区）以及双极磁结构对消区。前两种区域均能形成电流片,并且引起磁流体不稳定性,从而激发耀斑,但对消区和耀斑的关系不是很清楚,有待于理论工作者进一步探讨。 2、耀斑极大时间过后,光球和色球H₁₁=0线附近纵场梯度均有明显下降。 3、在强剪切区域（图1B区）,5324A横向磁场和H₁₁=0线之间的夹角在耀斑极大时间过后有明显增大,该现象表明磁能释放后,磁场剪切缓解。 4、耀斑初始亮点产生后磁场高度剪切区、新浮磁流区和双极对消区,其触发耀斑的作用和周围的磁场环境有密切关系,特别是象具有磁海湾结构这样的活动区,似乎更容易产生耀斑。 5. 该活动区色球磁场位形,较光球磁场位形复杂,主要表现在:色球的纵场出现了一些磁弧岛结构,其原因可能是光球之上的磁力线高度剪切区及扭绞所致。0411更多还原

【Abstract】 The data of magnetic fields measured at PeI λ5324A and Hβ4864A were obtained during the 2B two-ribbon flare process on Jan 14,1989. The one of intial bright points of the flare was lo cated in the inversion line of the concellation region, and the others were located near the H11=0 line where the shear of longitudinal magnetic fields was very strong. We found that the gradient of longitudinal magnetic fields near the H11=0 obviously decreased and the shear region had relaxed after the solar flare. The umbral flare was closely related to the changes of chromospheric magnetic field.更多还原