Limb images at the north pole (solar distance: 0.57 AU, 1″ = 413 km on the surface). Left panel: from the bottom, C III, O VI, Ne VIII. The yellow dashed lines show the E-W range where the line intensities in right panel have been summed. Right panel: intensities of the three lines with distance above the limb, averaged over 250 pixels in the E-W direction. The limb is at 130″.