Search Publications
C III observable with IUE.
Nussbaumer, H.; Schild, H.
Theoretical emissivity ratios are presented for the C III UV multiplets at 977, 1176, 1247, 1908, and 2297 A. Proton-ion collision rates for the relevant transitions are calculated by using the semiclassical impact-parameter method as developed by Sahal-Brechot (1969). IUE observations of these multiplets in the planetary nebula NGC 7027, the slow…
The far-UV spectrum of the T Tauri star RU Lupi.
Liseau, R.; Gahm, G. F.; Fredga, K. +1 more
The spectrum of the T Tauri star RU Lupi from 1150 to 3100 A has been observed from the IUE satellite. It is rich in emission lines, seen superimposed on a background continuum and traceable from Ly-alpha to 3100 A. The region from 2000 to 3100 A is dominated by metal line emission of the same nature as previously observed in the optical region. T…
On the high resolution ultraviolet spectrum of P Cygni.
Macchetto, F.; Lamers, H. J. G. L. M.; Cassatella, A. +7 more
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 o…
The EUV spectra of young planetary nebulae.
Nussbaumer, H.; Schild, H.; Flower, D. R.
High- and low-resolution EUV observations of the possible young planetary nebulae V1016 Cyg, HM Sge, and IC 4997 are reported which were made with the IUE satellite over the wavelength ranges from 1150 to 1950 A and from 1900 to 3200 A. The strongest emission lines observed in V1016 Cyg are identified, the spectra of the three objects in the regio…
The ultraviolet spectrum of the eclipsing binary Epsilon Aurigae.
Hack, M.; Selvelli, P. L.
A UV spectrum of the eclipsing single-line spectroscopic binary Epsilon Aur is analyzed which was obtained by the IUE satellite in the wavelength range from 1150 to 3200 A. The continuous and line spectra are examined, and parameters of the binary system are derived. It is concluded that the system consists of an F0 Ia primary with an absolute vis…
The ultraviolet spectrum of comet Seargent 1978m.
Keller, H. U.; Owen, T.; Smith, A. M. +5 more
UV spectrograms of Comet Seargent (1978m) have been obtained with the IUE satellite in the low- (1.8-nm) and high- (0.1-nm) dispersion modes. In the long-wavelength region (189-340 nm) emission bands of OH, CS, CO2(+), NH, and CO(+) can be identified, and the rotational structure of OH could clearly be resolved. In the short-wavelength region (119…
The UV resonance lines of zeta 1 Sco.
Wolf, B.; Appenzeller, I.
The IUE satellite has been used to obtain high-resolution UV spectrograms of the extreme B1 supergiant Zeta-1 Sco. The observed line spectrum was found to be dominated by conspicuous P Cygni profiles or strongly blueshifted circumstellar absorption lines of the resonance transitions of Al II, Mg II, Si II, C II, Al III, Si IV, C IV, and N V, and o…
On the ultraviolet spectrum of Nova Cygni 1978.
Clavel, J.; Macchetto, F.; Cassatella, A. +4 more
Ultraviolet high- and low-resolution spectra of Nova Cygni 1978 have been obtained with IUE at three dates during the first month after its outburst (Sept. 13). The high-resolution spectrum of Sept. 28 is dominated, in the range 2300-2800 A, by broad undisplaced emission lines of singly ionized metals like Fe II, Cr II, and Mn II. The widths of th…
Short time changes in the terminal velocity of the stellar wind of alpha Cam ((O9.5 Ia).
Macchetto, F.; Lamers, H. J. G. L. M.; de Jager, C. +1 more
The UV spectrum of the star Alpha Cam (09.5 Ia) was observed for 72 hours continuously in September 1978, with IUE. During these three days the star shows gradual short-term changes of the edge velocity of the C IV and N V resonance lines. The change is largest for the lines formed at large distance from the star, and may be due to either UV-flux …
The ultraviolet spectrum and expansion velocity of eta Carinae from IUE observations.
Viotti, R.; Cassatella, A.; Giangrande, A.
Sunmary. The high resolution ultraviolet speotrum of Car was observel with lUE on May 22 ani 2 , 1978. High (civ, SiIV, FeIli, ani probably NV) and low ionization (Mgi, MgII, MnII, AllI, Fell, eto.) lines have been identified with absorption and/or emission oomponents. Most resonance lines have three absorption components, the interstellar line, a…