Coronal loop hydrodynamics. The solar flare observedon November 12 1980 revisited: the UV line emission

Abstract

We revisit a well-studied solar flare whose X-ray emission originating from a simple loop structure was observed by most of the instruments on board SMM on November 12 1980. The X-ray emission of this flare, as observed with the XRP, was successfully modeled previously. Here we include a detailed modeling of the transition region and we compare the hydrodynamic results with the UVSP observations in two EUV lines, measured in areas smaller than the XRP rasters, covering only some portions of the flaring loop (the top and the foot-points). The single loop hydrodynamic model, which fits well the evolution of coronal lines (those observed with the XRP and the \FeXXI 1354.1 Åline observed with the UVSP) fails to model the flux level and evolution of the \OV 1371.3 Åline.