Cusp-shaped structure of a jet observed by IRIS and SDO
  On 29 August 2014, the trigger and evolution of a cusp-shaped jet were captured in detail at 1330 {\AA} by the Interface Region Imaging Spectrograph.At first, two neighboring mini-prominences arose in turn from low solar atmosphere and collided with a loop-like system over them. The collisions between the loop-like system and the mini-prominences lead to the blowout and then a cusp-shaped jet formed with a spire and an arch-base.   In the spire, many brightening blobs originating from the junction between the spire and the arch-base, moved upward in a rotating manner and then in a straight line in the late phase of the jet. In the arch-base, dark and bright material simultaneously tracked in a fan-like structure and the majority of the material moved along the fan's threads.   At the later phase of the jet's evolution, bidirectional flows emptied the arch-base, while down-flows emptied the spire, thus making the jet entirely vanish. The extremely detailed observations in this study shed new light on how magnetic reconnection alters the inner topological structure of a jet, and provide a beneficial complement for understanding current jet models. 
Zhang Yuzong and Zhang Jun
astro-ph.SR