  Solar eruptions are explosive disruption of coronal magnetic fields, and
often launch coronal mass ejections into the interplanetary space.
Intriguingly, many solar eruptions fail to escape from the Sun, and the
prevailing theory for such failed eruption is based on ideal MHD instabilities
of magnetic flux rope (MFR); that is, a MFR runs into kink instability and
erupts but cannot reach the height for torus instability. Here, based on
numerical MHD simulation, we present a new model of failed eruption in which
magnetic reconnection plays a leading role in the initiation and failure of the
eruption. Initially, a core bipolar potential field is embedded in a background
bipolar field, and by applying shearing and converging motions to the core
field, a current sheet is formed within the core field. Then, tether-cutting
reconnection is triggered at the current sheet, first slow for a while and
becoming fast, driving an erupting MFR. Eventually, the rise of MFR is halted
by the downward magnetic tension force of the overlying field, although the MFR
apex has well exceeded the critical height of torus instability. More
importantly, during the rise of the MFR, it experiences a significant rotation
around the vertical axis (with a direction contrary to that predicted by kink
instability), rendering the field direction at the rope apex almost inverse to
the overlying field. As a result, a strong current sheet is formed between the
MFR and the overlying flux, and reconnection occurring in this current sheet
ruins completely the MFR.

Solar and Stellar Astrophysics;Plasma Physics;Space Physics