Left: STEREO-B EUVI 195 Å difference image (at the time indicated with respect to 12:11:28.475 UT). Right: SDO AIA 131 Å image ratio (at the time indicated with respect to a previous image at 12:18:57.620 UT). Overlaid are the loop trace (red thick line with dashed lines for portion behind the limb in right panel), the SDO limb (blue) and heliospheric grid lines spaced by 10 degrees (orange dashed lines).