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The white dwarf companion of the barium star ZET Cap.
Boehm-Vitense, E.
It is shown that the barium star Zeta Cap has a white dwarf companion with a mass of approximately 1.0 solar masses and an effective temperature of 23,000 K. Strong emission lines and very deep reversals in the Mg II emission line cores indicate circumstellar gas which may be due to mass transfer in the system. The Ba star HD 65699 also shows the …
Spectrophotometry of dwarf novae in the wavelength range of 1250-7500A.
Pringle, J. E.; Bath, G. T.; Whelan, J. A. J.
The paper presents spectrophotometric observations of three southern dwarf novae BV Cen, EX Hya and VW Hyi in the wavelength range 1250-7500 A. BV Cen and EX Hya were observed in quiescence and VW Hyi on the decline from outburst. The received energy flux for BV Cen peaks at visible wavelengths, where the spectrum of a late G-star is evident. Both…
Evidence for hot gaseous coronae around the Magellanic clouds.
Savage, B. D.; de Boer, K. S.
High-dispersion IUE far-UV spectra were obtained for five stars in the LMC and two stars in the SMC. At Magellanic Cloud velocities, all the spectra exhibit very strong interstellar lines of Al III, Si IV, and C IV, in addition to the usual lower ionization stage lines associated with H I region absorption. In two stars interstellar N V is also de…
Simultaneous ultraviolet, optical and X-ray observations of the X-raysource Vel X-1 (HD 77581).
Davis, R. J.; Raymond, J. C.; Hammerschlag-Hensberge, G. +17 more
UV spectra (obtained by the IUE) of HD 77581, associated with the binary X-ray source Vela X-1, show a spectrum typical of an early B-type supergiant. However, the P Cygni profiles of strong resonance lines show substantial variations with orbital phase. These variations can be ascribed to the changing ionization state in the stellar wind caused b…
Recombination spectrum and reddening in NGC 1068.
Persson, S. E.; Matthews, K.; Soifer, B. T. +8 more
Measurements of the emission-line intensities of NGC 1068 have been made over the wavelength range extending from rest wavelengths equal to 1216 A to 1.875 micron. The data, plus other available emission-line data, can be explained in terms of a simple model where the emission lines are formed in an H II region, and the line ratios are consistent …
The outher atmospheres of cool stars. VII. High resolution, absolute flux profiles of the MG II H and K lines in stars of spectral types F8 to M5.
Stencel, R. E.; Mullan, D. J.; Linsky, J. L. +2 more
We present high-resolution lUE spectra of the emission cores of the Mg II resonance doublet at 280 nm in a selection of 54 stars covering a range of spectral type from F8 to MS and of luminosity class from supergiant (Ia) to subgiant (IV). These spectra were obtained with the LWR echelle system onboard the IUE satellite, and have been calibrated i…
Mass loss from O-type stars.
Conti, P. S.; Garmany, C. D.
We determine mass loss rates for six O-type stars from the violet-shifted absorption profile of the resonance C IV and N V lines, using the IUE satellite and the high-resolution camera. The values are substantially below those of Of stars (which have optical emission lines) of similar luminosity.
Ultraviolet spectra of planetary nebulae. I. The abundance of carbon in IC 418.
Harrington, J. P.; Lutz, J. H.; Seaton, M. J. +1 more
IUE observations of IC 418 give fluxes in the lines C III λ1908, C II] λ2326, [O II] λ2470 and Mg II λ2800. Fluxes on the scale of F(Hβ) = 100 are obtained using a computed [O II] branching ratio F(λλ7320,30)/F(λ2470) and an observed ratio F(λλ7320, 30)/F(Hβ). The deduced carbon abundance is log {C} = 8.85 ± 0.2 compared with log {C} = 8.67 ± 0.1 …
International Ultraviolet Explorer observations of M 87.
Capaccioli, M.; Holm, A. V.; Oke, J. B. +1 more
A spectrum of M87 obtained in the 1150-2000 A spectral range by the IUE is discussed. The visual and UV energy distribution of the nucleus of M87 reveals an essentially continuous curve from 1300 to 10,500 A, and a turnup in flux below 2200 A. It is shown that this turnup is not a consequence of scattered light in the instrument, while a plot of t…
The UV spectrum of AE Aqr.
Jameson, R. F.; King, A. R.; Sherrington, M. R.
Ultraviolet spectra of the cataclysmic variable AE Aquarii obtained by the IUE satellite are reported. They show strong emission lines on a weak continuum. It is shown that while Mg II, Ca II and some L-alpha emission probably arise in optically thin regions of the accretion disc, the higher ionization species must be radiatively produced outside …