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Studies of the Chamaeleon star-forming region. II. The pre-main-sequence stars HD 97048 and HD 97300.
The, P. S.; Wesselius, P. R.; Tjin-A-Djie, H. R. E. +1 more
Photometric observations in the visual, near infrared, and far infrared (IRAS), and UV(IUE) and IDS spectra are presented of the pre-main-sequence stars HD 97048 and HD 97300. The spectral energy distribution between 0.1 and 100 µm is obtained, and corrected for foreground and circumstellar extinction. Distances are derived and the infrared …
The optical and X-ray decline of V 0332+53 (X 0331+53, BQ Cam).
van der Klis, M.; Charles, P. A.; Corbet, R. H. D.
The authors present optical spectra of the X-ray transient V 0332+53 (BQ Cam). The equivalent width of the Hα emission line in the spectrum has declined by a factor ≡2 compared with previous observations. This is interpreted as showing that V 0332+53 is surrounded by an evolving circumstellar envelope. EXOSAT observations failed to detect X-ray em…
New observational results of the LMC-S DOR variable R 127 during outburst.
Stahl, O.; Wolf, B.
A study of the long term photometry of the LMC-S Dor variable R 127 indicates that it has had an extremely bright phase in August, 1984. Echelle spectrograph and IUE high dispersion spectra taken during this phase are compared with coude and IUE spectra taken during phases of intermediate brightness in 1982-1985. During the brightest phase, R 127 …
A study of UV spectra of zeta Aur/VV CEP systems. VIII. Chromospheric ionization and opacity.
Schroeder, K. -P.
Using 25 high resolution IUE spectra of Zeta Aur, 32 Cyg and 31 Cyg taken during chromospheric eclipse, the Fe I/Fe II ionization equilibrium has been determined empirically as Fe I/Fe II of about 10 exp -3.5. Fe is ionized by UV radiation from the B star companion while recombination is controlled by electrons from collisionally ionized hydrogen.…
Detailed analysis of the ISM toward dzeta OPH and 9 Sgr.
Pottasch, S. R.; Pwa, T. H.
Data from high-resolution spectra obtained with the IUE at 115-210 nm and 185-310 nm toward Zeta Oph and 9 Sqr are combined with published laboratory atomic and molecular data and supplementary Copernicus FUV observations to determine the abundances, temperatures, and densities in both H I clouds and the Zeta Oph H II region. The results are prese…
Optical and X-ray observations of 4U 2129+47/V1727 CYG in an extended quiescent state.
Pietsch, W.; Gottwald, M.; Graser, U. +1 more
Observations of the 5.h2 h X-ray binary 4U2129 + 47/V1727 Cyg for more than one orbital cycle on September 29 and October 4, 1983 with the ESA X-ray satellite EXOSAT failed to detect the source in the low and medium X-ray energy band. Quasi-simultaneous UBV photometry using the 2.2 m telescope at the German-Spanish Astronomical Center, …
The soft X-ray superoutburst of VW Hydri.
Heise, J.; van der Woerd, H.; Bateson, F.
The dwarf nova VW Hyi has been monitored with Exosat, during and shortly after the optical superoutburst of November 1983. VW Hyi appears to be a very soft X-ray emitter, and is marginally detected in the hard (1 to 6 keV) X-ray range. The soft X-ray emission increased by two orders of magnitude during outburst, with the dominant emission at wavel…
The accretion of supergiant wind material onto the hot companion in zeta Aurigae binaries.
Reimers, D.; Che-Bohnenstengel, A.
This paper is an attempt to interpret the behaviour of the high excitation C IV and Si IV resonance lines in the course of a period of the Zeta Aurigae binary systems. Three distinct phenomena have been observed: shock front emission, accretion wake absorption and accretion disc emission. At the C IV and Si IV emission regions the electron tempera…
The ultraviolet variability of the symbiotic star HBV 475. III. The periodicity of HBV 475.
Schmutz, W.; Vogel, M.; Nussbaumer, H.
The symbiotic star HBV 475 (= V1329 Cyg) shows periodic variations in its spectrum, both in flux and in the wavelength positions of the emission lines. New IUE observations, extending to the October 1985 flux maximum, allow an improved period and phase determination. The periodic variation of the line profiles are interpreted as being due to illum…
Mass loss from central stars of planetary nebulae : the nucleus of NGC6543.
Grewing, M.; Bianchi, L.; Cerrato, S.
Low and high resolution spectra of the nucleus of NGC 6543 were analyzed in the UV range (1150-3200 A). From the continuum energy distribution, the extinction towards this object was estimated to be E(B - V) = 0.08, and an effective temperature (80,000 K) was derived for the central star by comparison with pure-He model atmospheres for hot high gr…