PFSS context for the long-duration type IV event, computed from ADAPT/GONG boundary maps with source-surface radius R_ss = 2.5 R_⊙. Left panels: radial magnetic field B_r at the PFSS source surface (red: B_r > 0, blue: B_r < 0); the source-surface PIL is shown in black. Squares mark the Carrington longitude/latitude of each observing spacecraft projected onto the source surface at representative times in the three visibility windows: (a) Solar Orbiter (2025 August 21 21:30 UT), (b) Wind and Parker Solar Probe (2025 September 4 23:00 UT), and (c) STEREO-A (2025 September 8 04:45 UT). Right panels: PFSS field lines traced from r = 1.2 R_⊙ and rendered from the corresponding spacecraft viewpoint; closed field lines are white and open field lines are colored by polarity (red: B_r > 0, blue: B_r < 0). The PIL is located roughly ∼90° eastward of each projected spacecraft longitude at these epochs, suggesting that the relevant helmet streamer lies near the visible east limb from each viewpoint.