Successive stages of magnetic reconnection associated with the flux rope eruption in a multiple-ribbon solar eruptive flare

In this work, we present multi-wavelength study of an M8.7 class solar flare that occurred on 2014 December 17 from active region NOAA AR 12242. SDO/AIA, SDO/HMI, GOES and RHESSI data are used to analyses this event. This event consists of three different set of flare ribbons; circular, parallel, and remote ribbons. The event can be expressed by the three phases i.e., pre-eruptive, breakout (or null point) reconnection and standard reconnection phases. Magnetic field analysis reveals the presence of fan-spine type magnetic configuration over the active region. We interpret this event in the following three stages of reconnection. First, the tether cutting reconnection forms the flux rope and allows its slow upward evolution from a bipolar region that exists inside the fan-dome. Second, the reconnection takes place at the magnetic null that results in the formation of the circular ribbon over the outer negative polarity region at the foot points of the fan dome. Finally, the standard reconnection occurred underneath the erupting flux rope that results in the formation of parallel ribbons on both side of the inner s-shaped PIL inside the fan-dome. For the very first time, we report the formation of circular ribbon prior to the formation of parallel ribbons in such type of flare events, which provides a clear evidence that the breakout type magnetic reconnection at the magnetic null allows the eruption of the flux rope, and hence the standard reconnection in a typical fan-spine magnetic configuration. (author)