Search Publications
Accretion of mass in Algol.
Molaro, P.; Cugier, H.
Several high resolution IUE spectra of Algol taken in 1978 and 1979 are analysed. Variable additional absorption components for the ultraviolet resonance lines of Mg II, Al III, and Si IV are detected. The additional components show eclipsing effects indicating that they originate in a region near the primary star, Algol A. Moreover, their behavio…
The stellar population of the nucleus of M 33 from an analysis of itslambda-lambda 1200-3000 A spectrum.
Benvenuti, P.; Dodorico, S.; Ciani, A.
The λλ1200 - 3000 Å spectrum of the nucleus of M33 is used in conjunction with U, B, V photometry as input to a linear programming method to determine the stellar population of the system. No astrophysical constraints but modifications in the stellar library (which includes Population II objects) were used to explore different evolutionary histori…
Detection of diffuse LY alpha emission from cD galaxy in Abell 1795.
Norgaard-Nielsen, H. U.; Jorgensen, H. E.; Hansen, L.
The authors report the discovery of diffuse Lyα emission from the cD galaxy in Abell 1795 which has a high X-ray derived mass accretion rate. The Lyα emission coincides with the main optical filamentary structures and the Lyα/Hβ ratio is close to the recombination v…
Mass loss from the central star of NGC 3242.
Pottasch, S. R.; Hamann, W. -R.; Kudritzki, R. -P. +1 more
The central star of NGC 3242, which was classified to be of "continuous type" before Kudritzki et al. (1981) discovered and analysed photospheric absorptions, has been observed with IUE in high resolution. The N V resonance doublet exhibits a weak P Cygni profile with photospheric components. Theoretical profiles are obtained from comoving-frame c…
A study of the Herbig Ae-type stars UX Ori and CD -44°3318 based on IUE spectra, and on visual and infrared photometry.
Djie, H. R. E. Tjin A.; Remijn, L.; Thé, P. S.
Far ultraviolet spectra of the two Herbig Ae stars UX Ori and CD -44°3318 are used to derive spectral types A2 III for UX Ori, and A0 - 1 III for CD -44°3318. The spectral energy distributions are in agreement with that of a Kurucz model with Teff = 9500K and log g = 4.0. In the near infrared both stars have a large excess of radiation,…
Abrupt changes in the C IV resonance lines of theta CR B.
Stalio, R.; Doazan, V.; Thomas, R. N. +2 more
It is noted that the Theta CrB far-UV spectrum changes from conspicuous presence, to complete disappearance, to reappearance at a higher velocity than the previous one, have occurred with a phase lag of about 3 years after the disappearance of a weak shell phase of short duration which was observed in the visible in 1979. This sequence is interpre…
Visual and ultraviolet spectrum of the eclipsing binary V367 Cygni.
Hack, M.; Engin, S.; Yilmaz, N.
V 367 Cyg is a single spectrum eclipsing binary (P = 18.6 d) classified as Beta Lyrae type. Spectroscopic observations during two successive cycles confirm previous studies and indicate that the shell spectrum does not vary greatly and does not present appreciable expansional velocity. The radial velocity of the shell lines may be explained by a r…
The UV variations of the symbiotic star CH Cygni from 1978 to 1981.
Hack, M.; Persic, M.; Selvelli, P. L.
The spectroscopic changes of CH Cygni from early 1978 to late 1981 are discussed with reference to several ultraviolet spectra obtained at the Villafranca Satellite Tracking Station. Correlations have been found to exist between the fluxes of the continuum and the fluxes of the forbidden and semiforbidden lines. Three new forbidden-line identifica…
Evolution of the ultraviolet coma of comet Austin (1982g.)
Feldman, P. D.; Keller, H. U.; A'Hearn, M. F. +6 more
Ultraviolet spectra of comet Austin (1982) obtained in July 1982 at heliocentric distances ranging from 1.10 to 0.81 AU preperihelion with the IUE reveal that the comet is very similar in chemical composition and appearance to comet Bradfield (1979X). In addition, the derived H2O production rate is found to vary with heliocentric distance as r to …
Far-ultraviolet spectra of the nuclei of globular clusters M 30, M 54, M 70.
Wamsteker, W.; Caloi, V.; Castellani, V. +1 more
IUE spectra in the low dispersion mode have been collected from the nuclei of the three galactic globular clusters NGC 6681 (= M70), NGC 6715 (= M54), and NGC 7099 (= M30). High UV fluxes are obtained from M54 which had been found earlier to be a real characteristic of the cluster population, suggesting a possible connection of this cluster with E…