Superposition of the detected spots. For clarity and to guide the eye, left panel: spots detected in the first four epochs (epoch D–G; see Table 1). Right panel: spots detected from epochs M to R. The contour levels are 0.3, 0.4, 0.5, 0.65, 0.80, and 0.95 times the peak flux of each image. Triangles indicate the emission peaks of spot 1; squares and circles correspond to spot 2 and 3, respectively.