Magnetic fan-spine topology showing the UV brightening at the 3D null and QSEB at one of the footpoints of the fan surface. This resembles the cartoon shown in Fig. 2d. The QSEB also has a dipole configuration. The B_LOS map shows the footpoints of these two phenomena: orange crosses denote the projection of the null point of the UV brightening, and yellow circles denote the footpoints of the fan surface. Blue and red markers are the negative and positive footpoints of the dipole of the QSEB, respectively. The QSEB and UV brightening share a common negative polarity, and the QSEB occurs at the positive polarity where the footpoints of the fan surface are located (intersection of red and yellow dots around x, y = 3″, 2.2″). The contours are at 1σ above the noise level. The dashed pink box denotes the region used to calculate the magnetic flux and magnetic energy for the QSEB, as shown in Fig. 10.