TEMPORAL AND SPATIAL VARIATION OF PHYSICAL PARAMETERS IN A QUIESCENT PROMINENCE

The emission lines He 3889 angstrom, H8 and Ca+IR3 are observed simult aneously in a prominence over a total of 4 hours. The time variations of the He 3889 / H8 emission ratio R, the thermal and the non-thermal line broadenings T(kin) and xi, respectively, are compared with those of the Doppler shift, V(D), for 10 spatial locations along the slit. T he time-averaged spatial variations along the slit show an increase of R, T(kin), and xi with height related to a decrease of the H8 emissio n, E(tot)(H8), in agreement with other authors. The short-time fluctua tions show that quasi-oscillations, known from Doppler shifts, also ex ist for other physical parameters. The long-term variations over the t otal of 4 hours indicate a smooth increase of R, T(kin), and xi at the upper parts of the prominence, resembling the known spatial behaviour of these parameters at prominence edges. Also the well known anti-cor relation of the emission ratio R and the E(tot)(H8) occurs in the long -term behaviour. We suggest that the decrease of E(tot)(H8) parallel w ith the increase of R might be related to a dissolution of the promine nce yielding a smaller density of fine-structures.