The formation mechanism of two homologous transequatorial loops (TLs) of July 7–8, 1999 (SOL1999-07-07) is studied. The TLs connected active region AR 8614 from the northern hemisphere to AR 8626 in the southern hemisphere. The first TL appeared as a distinct structure at 12:49 UT on July 7, the second TL appeared at 06:21 UT, on July 8. Important results are obtained in this analysis: (i) The configuration of the two TLs is similar in X-rays. (ii) The sizes of the two active regions related to the TLs increased before and during the formation of the two TLs, this induced the expansion of their coronal loops. (iii) Both TLs formed globally on a time scale shorter than 110 min (time resolution of observations). (iv) An X-shaped coronal structure was observed. This observational evidence suggests that the two TLs formed by the same physical mechanism, magnetic reconnection, between the two expanding magnetic configurations of the two ARs.

中文翻译：

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两个同源越赤道环的形成

研究了1999年7月7-8日(SOL1999-07-07)两个同源越赤道环(TLs)的形成机制。TLs 将北半球的活动区 AR 8614 连接到南半球的 AR 8626。第一个 TL 出现在 7 月 7 日 12:49 UT，第二个 TL 出现在 06:21 UT，7 月 8 日。在该分析中获得了重要结果：（i）两个 TL 的配置相似在 X 射线中。(ii) 在两个 TLs 形成之前和期间，与 TLs 相关的两个活性区域的大小增加，这导致了它们的冠状环的扩张。(iii) 两个 TLs 都是在短于 110 分钟的时间尺度上形成的（观测的时间分辨率）。(iv)观察到X形冠状结构。