Eruptive characteristics of the flare. (a1)–(f1) Eruptive details observed by the AIA 131 Å passband. The white arrows in (f1) point out two sets of post-flare loops. The two dashed boxes in (f1) are the same as the ones in Fig. 4g, enclosing the northern and southern sets of loops. The polarities , N₁,P₂, and N₂ are marked in panels a1 and f1 for reference. (a2)–(f2) Eruption details captured by AIA 304 Å passband, showing the eruption of the filament. The photospheric B_z is overplotted in panel a2 for comparison, with white (green) contours for the positive (negative) polarities. The contour levels are −600 G and 600 G. (a3)–(f3) Flare ribbons observed in the 1600 Å passband. The RHESSI HXR sources in the 12–25 keV energy bands are overplotted in panels a1, b1, c1, d2, and e1, with contour levels at 60% and 90% of the peak flux. The blue rectangle in panel a2 has the same FOV as the one in Fig. 1b. An associated animation lasting form 09:00 to 10:10 on 2012 July 4 is available online, incorporating the details of the precursor and the main flare, and a C9.7-class flare lasting from 09:00 to 09:09. Brightenings at the BP region and flare ribbons during the C9.7-class flare are indicated by arrows in the movie. The BP region is also enclosed by a green rectangle, which is the same as the one in Fig. 1b. See relevant discussion in Sect. 4.