On the high resolution ultraviolet spectrum of P Cygni.
Macchetto, F.; Lamers, H. J. G. L. M.; Cassatella, A.; Heck, A.; Stickland, D.; Benvenuti, P.; Selvelli, P. L.; Penston, M.; Beeckmans, F.; Clayel, J.
Netherlands, Spain
Abstract
The paper discusses ultraviolet spectra of P Cygni in the range of 1150-3200 A obtained at VILSPA from the IUE satellite during April-August, 1978. The spectrum is dominated by blue-shifted absorption lines of singly and doubly ionized metals like Fe, Mn, Ni, Cr, and Ti formed in the expanding envelope. The observations also suggest the presence of plateaus in the velocity vs envelope radius relation connected with possible changes in the ionization conditions through the envelope. A curve of growth analysis has been carried out for the Fe II lines. A rough estimate has been given to the energy blocked by the blue-shifted absorption lines.