STEREO/COR1 Ahead (left) and Behind (right) images at 3:40 UT (before the CME, top panels) and at 4:00 UT (during the CME, bottom panels). The arrow in the image of the top-left panel points at a faint and short streamer visible in the FOV of COR1-A, before the CME propagation. In the images of the bottom panels, paths 1 are along a radial direction at 73° and 290° PA (measured counterclockwise from North) in the FOV of COR1-A and COR1-B, while paths 2 are perpendicular to the respective paths 1 and extend from 42° to 104° PA and from 257° to 323° PA in the FOV of COR1-A and COR1-B.