Search Publications
Missions
Journals
Publication Years
The ultraviolet variability of early-type supergiants.
Underhill, A. B.
Four early-type supergiants - HD 79186 (B5 Ia), HD 96919 (B9 Ia), HD 105056 (ON9.7 Iae), and HD 148379 (B2 Iae) - have been observed with the low-resolution spectrographs of IUE in the large aperture on 14 days. The behavior of the ultraviolet fluxes with time is studied. The light from all four stars seems to vary. Typically the dispersion about …
Search for discrete gamma-ray sources emitting at energies greater than 10(exp15) eV.
Samorski, M.; Stamm, W.
The data of the extensive air shower experiment at Kiel have been scanned systematically for possible discrete γ-ray sources in the energy range E > 1015 eV and in the declination band δ = 25° - 75°. Photon fluxes for celestial positions with the statistically most significant excesses of showers and 3 σ upper limit photon fluxes for…
The IUE spectrum of gamma 1 Velorum.
Sahade, J.; Hernandez, C. A.
Gamma(1) Vel is suggested by IUE observations to be an interacting binary system with nonthermal energy sources and the possibility of two high electron temperature regions, as well as mass outflow from one of the components. A UV continuum is obtained which fits the Kurucz (1979) LTE model atmosphere computations for an effective temperature of 2…
New observations of the CIV and N V resonance doublets in the planetary nebula NGC 3918.
Pena, M.; Torres-Peimbert, S.
We present new short wavelength high dispersion lUE measurements of the resonance doublets 1238/1243 of N V and 1548/1551 of C IV. The observed intensity ratios are of 1.87±0.15 for N V and 1.83±0.11 for C IV; compatible, within the observational uncertainties with the expected ratio of 2.
A search for chromospheric emission in TU Cassiopeiae spectra.
Henden, A. A.; Cornett, R. H.; Schmidt, E. G.
The authors have searched high-resolution spectra of the multimode cepheid TU Cas for evidence of chromospheric emission. Spectral regions covered include the Ca II near-IR triplet near 8600 Å, Hα, Ca II H and K, Mg II h and k; phase coverage in both primary and secondary modes was reasonably complete. There was no evidence for changes other than …
The IUE blaze function in the MG II region.
Morossi, C.; Vladilo, G.; Allocchio, C.
To obtain reliable emission profiles of Mg II resonance lines from the IUE data it is absolutely necessary to perform a good ripple correction of the IUE net spectrum. An experimental blaze function (valid for the IUE orders from 88 to 79) has been derived as the ratio between the IUE data and those of the Copernicus satellite: in fact, the latter…
Observations of Binaries and Evolutionary Implications
De Loore, C.
Comparison of the characteristics of groups of stars in various evolutionary phases and the study of individual systems allow to make estimates of the parameters governing mass loss and mass transfer. Observations enable us in a few cases to determine geometric models for binaries during or after the mass transfer phase (disks, rings, common envel…
IUE observations of W UMA systems AE Phoenicis and TY Mensae.
Rucinski, S. M.
SWP spectra of AE Phe and TY Men are presented and discussed. The spectrum of AE Phe is typical in showing strong emission lines which originate in the chromosphere and transition region. On the basis of the strength of the He II emission line the author predicts that AE Phe should be a moderately strong X-ray source. The spectrum of TY Men is too…
Comparison of Ultraviolet Spectra from Solar Type Stars
Wamsteker, W.; Greve, A.
We compare high-resolution spectra from the Sun and the four solar-type stars 16 Cyg A, 16 Cyg B, HD 32008, HD 34411 obtained with IUE in the wavelength range 2650-2930 Å. The comparison is made for peak intensities between absorption lines. At the level of accuracy of the IUE observations, the stars 16 Cyg A, 16 Cyg B, HD 34411 are indistinguisha…
A comparison between various UV photometric systems for late-type stars.
Cacciari, C.; Wamsteker, W.; Norgaard-Nielsen, H. U. +1 more
Ultraviolet absolute photometry and spectrophotometry obtained for late-type stars with the TD1, OAO-2, ANS, and IUE satellites are compared. Strong colour effects are found in the TD1 2740 Å band, and, to a lesser extend, in the OAO-2 2980 Å band. The reason for these effects is believed to be due to red leaks in the sensitivity functions. For th…