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IUE observations of weak G-band stars.
Sneden, C.; Parthasarathy, M.; Bohm-Vitense, E.
High- and low-resolution ultraviolet spectra of several weak G-band giants have been obtained with the IUE satellite, to derive Be abundances and to search for degenerate companions. The abundances of Be in these stars are about log epsilon (Be) approximately -0.5. These values are in good agreement with the Be abundances of Hyades giants, and are…
Ultraviolet spectroscopy of hot young stars with infrared excesses : NGC 2264 - W 46, W 90 and W 100.
Sitko, M. L.; Simon, T.; Meade, M. R.
New ultraviolet data are combined with optical data to investigate the wavelength-dependent extinction of the stars W46, W90, and W100 in the young galactic cluster NGC 2264. The observations of W90 confirm the existence of anomalous (circumstellar) dust extinction with a ratio of total to selective extinction, R greater than 7. This extinction is…
Ultraviolet observations of the Be star MU Centauri during its recentactive phase.
Peters, G. J.
IUE and Copernicus ultraviolet observations and ground-based image-tube and direct spectrograms of the pole-on Be star Mu Cen have been combined to investigate the nature of this star's activity during its Balmer emission-line episode of 1980-81. Within the uncertainties of the observations, the UV data show no evidence for a wind, a classical-typ…
Ultraviolet analysis of the peculiar supergiant HD 112374 = HR 4912.
Bohm-Vitense, E.; Proffitt, C.
The ultraviolet energy distribution of the metal-poor supergiant HD 112374 is analyzed based on observations from the International Ultraviolet Explorer (IUE) satellite for the region between 1200 and 2000 A. A discontinuity was found in the UV spectra at 2600 A which confirmed the low-abundance of heavy elements found by Luck et al. (1983). Value…
Far and extreme-ultraviolet spectrophotometry of hot white dwarfs : prospects for the determination of the He/H ratio in DA stars.
Wesemael, F.; Green, R. F.; Liebert, J.
The various spectroscopic methods currently available to determine the He/H ratio in hot DA white dwarfs are compared and contrasted. The observation of the optical He II λ4686 line, as well as that of the λ1640 line with the low-dispersion IUE camera, can only be wsed to determine the helium abundance for log (He/H) > -3. Low-resolution (λ/Δλ …
Anomalous C IV and SI IV resonance lines in 36 Lyncis.
Sadakane, K.
Anomalously strong resonance lines of C IV and Si IV are found in the UV spectrum of the chemically peculiar star 36 Lyncis. The C IV resonance lines near 1550 Å are not found in about 40 other middle or late B-type main-sequence stars. The C IV lines (Wλ ≡ 1.0 Å) are stronger than the Si IV lines (Wλ ≡ 0.7 Å) in 36 Lyn and s…
Notes on the system TV Geminorum.
Underhill, A. B.
Low-resolution SWP spectra and high-resolution LWR spectra of the SRc variable star TV Gem have been studied. The available ultraviolet spectrophotometry and UBV photometry of the system can be interpreted in terms of the blended light from a B3.5 IV star and an M1 Iab star. The separation of the two stars is less than about 3 arc sec. Since the m…
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…
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 …
Multifrequency observations of the quasi-stellar object Ton 1542.
Bruhweiler, F. C.; Miller, H. R.; Worrall, D. M. +3 more
The authors present single-epoch multifrequency data for the radio-quiet low-redshift QSO Ton 1542, spanning radio through ultraviolet wavelengths. They measure a 3σ upper limit of 9.2 mJy for the 20.3 GHz flux density. The first ultraviolet spectrum of this object is presented and discussed. The authors find a particularly strong excess of flux d…