A study is presented about the formation of a loop prominence system (LPS) on May 13, 1971. The development of the phenomenon in found the follow the model of Jefferies and Orrall, and was associated with small radio bursts and several kind SID. From the spectral analysis a temperature of 13200 K has been deduced and a density of hydrogen atoms n(H) = 10¹⁰ cm⁻⁸ estimated. The existence of inclined emissions probably produced by rotatory motions is discussed. From the radio-data analysis it was inferred that an impulsive and a thermal component were present, the length of the emitting plasma cloud was found to be about 56000 Km. The LPS appeared, in accordance to previous results, in a región producing proton fiares. The paper in full will be published in Solar Physics.Asociación Argentina de Astronomí
