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Analysis of the IUE and optical spectra of the peculiar Be star HD 87643.
Pottasch, S. R.; de Freitas Pacheco, J. A.; Gilra, D. P.
IUE observations of the peculiar Be star HD 87643 are presented. The broad absorptions seen at 2400 A, 2600 A, and 2750 A are interpreted as being produced by Fe II transitions from the ground-state and the low lying metastable states. The optical lines of Fe II seen in emission are most probably excited by continuum fluorescence. This interpretat…
The ultraviolet spectrum of KQ PUP (Boss 1985).
Altamore, A.; Viotti, R.; Giangrande, A.
The high resolution spectrum of the VV Cep star KQ Pup observed with the IUE satellite during 1979 and 1980 is summarized. More than 600 lines have been identified between 1190 and 3228 A. Two main line systems are present, a broad absorption line system, which includes high ionization lines from N V, C IV, Si IV and Al III, and narrow P Cygni lin…
Interstellar extinction in the Perseus arm.
Nandy, K.; McLachlan, A.; Morgan, B. L.
Individual UV extinction curves for nine stars located in the direction of h and Chi Persei in the distance range 0.6-4.4 kpc are presented. The observations were made with the International Ultraviolet Explorer (IUE) in the low dispersion mode with large aperture. The sample has been enlarged by the use of available UV and visible data for 32 red…
Optical and ultraviolet observations of the X-ray globular cluster BO 158 in M31
Cacciari, C.; Bianchi, L.; Fusi Pecci, F. +2 more
It is pointed out that the study of the globular cluster system in a galaxy is very important for understanding the formation, dynamics, and chemical evolution of that galaxy. The present investigation represents an attempt to determine the population content of the globular cluster Bo 158 in M31 through the analysis of its energy distribution in …
Ultraviolet spectra of planetary nebulae. VII. The abundance of carbon in the very low excitation nebula HE 2-131.
Seaton, M. J.; Adams, S.
Features observed in infrared spectra suggest that certain very low excitation (VLE) nebulae have low C/O abundance ratios (Cohen & Barlow 1980; Aitken & Roche 1982). Fluxes in the multiplets [O II] sun2470 and [O II] λ2326 have been measured for the VLE nebula He 2-131 = HD 138403 using lUE high-dispersion spectra. An analysis …
The detection of ultraviolet photospheric absorption in the spectra of two Wolf-rayet stars.
Fitzpatrick, E. L.
Narrow, unshifted UV absorption lines, principally of Fe v, have been detected in the spectra of two Wolf-Rayet stars, HD 93162 (WN7) and HD 193793 (WC7). Both stars are known to show upper Balmer-line absorption but exhibit no periodic Doppler shifts that might indicate the presence of a companion. If intrinsic to the Wolf-Rayet stars, these line…
A spectrophotometric analysis of the hot helium-rich white dwarf HD 149499 B.
Sion, E. M.; Wesemael, F.; Guinan, E. F.
A comprehensive analysis of the hot helium-rich white dwarf HD 149499 B is presented based on International Ultraviolet Explorer ultraviolet spectra along with available optical spectra and photometry. Line strengths, line profiles, and continuum fluxes are analyzed in terms of a new grid of hot, high-gravity stellar atmospheres of mixed compositi…
International ultraviolet explorer observations of alf Sco.
Bernat, A. P.
IUE observations of the absorption spectrum of Alpha-2 Sco B2.5 V are presented. These lines arise from matter being lost by the red supergiant primary, Alpha-1 Sco M1.5 Iab, which is passing in front of the B star. There is a factor of 30 spread in the hydrogen column densities derived from different elements on the assumption of solar abundance …
Variability and mass loss in the extreme supergiant zet01 Sco.
Bianchi, L.; Cassatella, A.; Heck, A. +1 more
It is found that the photometric variability can be characterized by a unique relationship between the half-period and the amplitude in the V band. This kind of variability differs from that characterizing the best known pulsating stars. One explanation, advanced tentatively, is that p and g modes are simultaneously excited. What is considered a m…
UV observations of TT Arietis and the magnetic rotator hypothesis
Jameson, R. F.; King, A. R.; Sherrington, M. R. +1 more
TT Arietis, one of the brightest cataclysmic variables, mv~10.2-->11.0, is usually classed as a novalike variable, but after a recent dip in brightness to mv~14.5, Krautter et al.1 suggested it to be a dwarf nova in an extended high state. Photometric light curves2-4 generally show a sinusoidal light …