On 14 October 2014 the Sun Watcher with Active Pixels and Image Processing ( SWAP ) EUV solar telescope on-board the Project for On-Board Autonomy 2 ( PROBA2 ) spacecraft observed an eruption that led to the formation of perhaps the largest post-eruptive loop system seen in the solar corona in solar cycle 24 .
The initial eruption occurred at about 18:30 UT on 14 October , behind the East Solar limb , and was observed as a a coronal mass ejection and an M2.2 solar flare .
In the 48 hours following the eruption , the associated post-eruptive loops grew to a height of approximately 4 \times 10 ^ { 5 } km ( > 0.5 \mathrm { R _ { \odot } } ) at rates between 2–6 km \mathrm { s } ^ { -1 } .
We conclude from our observations of this event that ordinary post-eruptive loops and so-called post-flare giant arches are fundamentally the same and are formed by the same magnetic reconnection mechanism .