Running from top to bottom, these figures show the evolution of the sigmoid over three hours leading up to its final eruption. Columns 1 and 2 show results from the St Andrews model. The left column shows the strength of electric current predicted by the model and the central panel shows predictions of temperature. Column 3 shows the development of the sigmoid observed by Hinode. The model successfully predicts the shape of the sigmoid, internal structure and distribution of heat along its length. (Credit: NASA / STFC / ISAS / JAXA / A. Hood (St. Andrews), V. Archontis (St. Andrews))
