A: Difference between two processed SDO/AIA 17.1 nm images showing changes over two hours prior to the eclipse (14:48 and 16:48 UT), with arrows indicating active region 12672 (arrow 1) and 12671 (arrow 7) along with some erupting structures that will impact the outer corona, namely a joint eruption of active region 12672 (arrow 1) and a prominence in the southeastern corona (arrow 2). B: Difference between two processed SOHO/LASCO-C2 images from 17:24 and 17:36 UT, showing eruptions (arrows 3, 5 and 6) in the corona occurring at the time of the eclipse. The inner white circle represents the approximate size of the solar disk. C and D: PM-NAFE processed AIA data of the disk center active region (12671) at 13:00 and 14:00 UT, respectively. The arrows indicate changes in the PM-NAFE maps, likely due to a halo-CME erupting from this active region (see Section 2.3 for details on the image processing). An animation of panels “c” and “d” is available. The video begins on 2017 August 21st 12:00:05 and ends the same day at 14:59:41. The realtime duration of the video is 36 s.

(An animation of this figure is available.)

The video/animation of this figure is available in the online journal.