Authors: Satyam Agarwal (CSPAR, UAH, USA), Alphonse C. Sterling (NASA Marshall Space Flight Center, USA), Shibu K. Mathew (Udaipur Solar Observatory, PRL, India), Ronald L Moore (CSPAR, UAH), Qiang Hu (CSPAR, UAH), Ramit Bhattacharyya (Udaipur Solar Observatory, PRL, India)

Solar flares are explosive events caused by magnetic reconnection in the solar atmosphere. Those flares that are accompanied by a successful ejection of an erupting filament/prominence into the heliosphere are called eruptive, while those in which the eruption is stopped by the overlying magnetic field are called confined. Typically, flares have been observed to be of only these two types. Such flares can generally be explained by the standard flare model and hence are also called standard flares. However, over the past decade, a few cases of confined flares without any erupting structure have been reported. Such flares have been called atypical, and there is still much uncertainty about the mechanism that powers them. We present observations and a magnetic-reconnection scenario of a pair of atypical flares. Characteristic of atypical flares and indicative of slipping reconnection, the ribbons of each of our atypical flares (1) do not spread apart, and (2) grow longer by sequential brightening of new flare kernels. The two atypical flares are homologous and plausibly have homologous triggers. Using a nonlinear force-free field (NLFFF) extrapolation model, we approximated the coronal magnetic field and found two quasi-separatrix layers (QSLs) that are nearly rooted in the flare ribbons of the atypical flares. The observations and the extrapolated field together suggest a scenario in which the nearly simultaneous occurrence of many reconnections between magnetic field lines crossing at small angles (slipping reconnection) within each of the two QSLs produces the observed pair of atypical flares.