Temporal evolution of a selected BP (Lifetime: 1321 s), observed on 9 June 2009 in the Sunrise/SuFI Ca ii H passband. Time proceeds row by row and from left to right within each row. The red and yellow contours outline magnetic regions with opposite polarities of the line-of-sight magnetic field component and match the 3σ level in Stokes V. In the bottom-right panel, the trajectory of the BP is plotted. The arrow marks the sense of the motion. The time from UT midnight, in seconds, is shown in the upper-right corner of each frame. Note the irregular intervals between frames.