Ultraviolet and optical observations of a coronal transient with SOHO

A coronal transient was observed on 1997 March 6 at 1.6 R. over an active region on the east limb. We observed both the edge of horizontally compressed gas and the diffuse curtain of coronal material. The region was monitored for 4 hr, and the H I Ly alpha, O VI lambda lambda 1031.91, 1037.61, N V lambda lambda 1242.80, 1238.80, and O V] lambda 1218.35 lines were detected during the ejection evolution. The density, velocity, temperature, and oxygen abundance of the ejected plasma have been obtained from the observed spectra. Intermediate temperature lines of N V, O VI, and O V show a large enhancement, suggesting a quite narrow range of plasma temperature around 4 x 10(5) K. Doppler shifts of the ejected material evolve from an initial blueshift of 100 km s(-1) to a redshift of 145 km s(-1). The outflow velocity, as determined by Doppler dimming analysis of the O VI doublet, is only about 20 km s(-1).