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GD 323 : a white dwarf with a stratified H/He atmosphere ?
Sion, E. M.; Wesemael, F.; Liebert, J. +1 more
New optical and ultraviolet (IUE) spectrophotometry of the hot white dwarf GD 323 are presented. The optical spectra exhibit broad, shallow Balmer lines, together with weaker He I lambda-4471, lambda-4921 lines. However, the effective temperature and helium abundance derived from the optical spectrum appear incompatible with parameters derived fro…
The resonance lines of HG II in IUE spectra of chemically peculiar stars.
Leckrone, D. S.
High-dispersion IUE observations of the two resonance lines of Hg II, at 1650 and 1942 Å, are presented for two normal stars, ν Cap and π Cet; for the HgMn stars κ Cnc, µ Lep, 46 Dra, ι CrB, HR 4072, and χ Lup; and for the magnetic variable α2CVn. These peculiar stars have all been classified as Hg-rich on the basis of their stron…
Ultraviolet and optical spectroscopy of CN 1-1 (= HDE 330036).
Lutz, J. H.
Ultraviolet and optical spectra of Cn 1-1 are presented. This stellar object has strong emission lines superposed on the absorption spectrum of an F5 III-IV star. It has been called both a symbolic star and a planetary nebula. Optical spectra taken over a period of two years do not show any variations in radial velocities. The radial velocities of…
Coordinated UV and optical observations of the AM Herculis object E 1405-451 in thehigh and low sta
Maraschi, L.; Tanzi, E. G.; Motch, C. +5 more
Simultaneous UV and optical observations of the magnetic white dwarf binary E1405-451 taken in February 1983, March, and April are reported. In March the source was found in a low state analogous to those observed in AM Her. In this state the ultraviolet spectrum of E1405-451 can be interpreted as the emission from a hot white dwarf/T = 26,500 K, …
Ultraviolet observations of interstellar extinction near the Cepheus OB3 molecular cloud.
Savage, B. D.; Massa, D.
IUE data are used to derive UV extinction curves for O and B stars in the Cep OB3 association. These data are analyzed in conjunction with ANS photometry of additional association stars. While the level of the far-UV extinction differs greatly throughout the region the shape of the 2175 Å bump does not. The authors demonstrate that the different c…
LSS 4300 : a hot counterpart of upsilon Sagittarii and KS Persei ?
Drilling, J. S.; Schoenberner, D.
A number of recent observations indicate that the star LSS 4300 (HDE 320156) is a high-temperature analog of the hydrogen-deficient binaries Upsilon Sgr and KS Per. A preliminary model-atmosphere analysis based on high dispersion spectra obtained at Kitt Peak and Cerro Tololo yields Teff = 14,400 K, log (g) = 1.4, n(H)/n(He) = 0.003, and n(N)/n(C)…
Line profiles from supernovae.
Fransson, C.
The location and mechanism of 120-200-nm emissions from supernovae are investigated theoretically, and the results are applied to IUE observations of SN 1979c reported by Panagia et al. (1980). Analytical expressions are obtained for line profiles originating in the expanding photosphere behind the shock wave (using the two-level approximation) an…
IUE high resolution spectrophotometry of H LY alpha emission from the local interstellar medium
Bowyer, S.; Clarke, J. T.; Fahr, H. J. +1 more
IUE high dispersion spectra of resonantly scattered solar Ly alpha emission from H moving into the solar system with the local interstellar wind are reported which are based on observations conducted in April 1981 and April 1983. A heliocentric velocity of -29 + or - 5 km/s has been observed from the ISW component along with a surface brightness w…
Images in the rocket ultraviolet : photometry of M 101.
Bohlin, R. C.; Stecher, T. P.; Hill, J. K.
Three ultraviolet images of the Sc I galaxy M101 (NGC 5457) were obtained by a rocket-borne telescope, using a microchannel plate image intensifier coupled to IIa-O film, giving an effective wavelength of 2250 Å, a bandpass of 970 Å, and about 10arcsec resolution over an 80arcmin field. Extreme Population I dominates in the UV in the form of OB/H …
IUE spectrophotometry of the DA4 primary in the short-period white dwarf red dwarf spectroscopic binary Case 1.
Sion, E. M.; Wesemael, F.; Guinan, E. F.
Low-resolution ultraviolet International Ultraviolet Explorer spectra of the DA white dwarf Case 1 are presented. The spectra show the presence of the 1400 A feature, already discovered in several other DA stars, and of a shallower trough in the 1550-1700 A range. A model atmosphere analysis of the ultraviolet energy distribution of the Ly-alpha r…