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Absolute spectrophotometry of Wolf-rayet stars from 1200 to 7000 A : a cautionary tale.
Conti, P. S.; Garmany, C. D.; Massey, P.
It is demonstrated that absolute spectrophotometry of the continua of Wolf-Rayet stars may be obtained over the wavelength range 1200-7000 A using IUE and optical measurements. It is shown that the application of a 'standard' reddening law to the observed data gives spurious results in many cases. Additional UV extinction is apparently necessary a…
The origin of low-velocity absorption components in the MG II resonance lines of hybrid-chromosphere stars.
Linsky, J. L.; Brown, A.; Drake, S. A.
It is argued that the low-velocity absorption features seen in the Mg II resonance lines of seven confirmed and three probable hybrid-chromosphere stars are interstellar rather than circumstellar in origin. From a comparison of radial velocities based on all available spectra in the International Ultraviolet Explorer (IUE) archives with estimates …
EXOSAT observations of GH 2215^-086 : detection of the X-ray pulse period
Watson, M. G.; McHardy, I. M.; Cook, M. C.
A 2.8 hr observation of the intermediate polar H2215 - 086 using the Exosat Medium Energy experiment has revealed a strong, quasi-sinusoidal modulation of the hard X-ray flux with a period (20.65 + or - 0.32 min) consistent with, and in phase with, that of the large amplitude optical variations. The detection of this hard X-ray modulation confirms…
Two multifrequency observations of 3C 371.
Bruhweiler, F. C.; Miller, H. R.; Worrall, D. M. +14 more
We present observations of 3C 37t, made at frequencies from the radio to the ultraviolet, which were coordinated during two short time intervals separated by 3 months. We also present 1 keV X-ray flux densities measured at a different time. The multifrequency measurements indicate spectral steepening at visual wavelengths, and that an extrapolatio…
IUE low dispersion observations of symbiotic objects.
Sahade, J.; Fontenla, J. M.; Brandi, E.
The results of the study of low dispersion IUE ultraviolet spectra of 20 symbiotic stars and of the binary RY Scuti are presented in tables and graphs. The continuous and the line spectra are analyzed and discussed. Variations in line intensity and in the continuum are reported.
Ultraviolet flare on lambda Andromedae.
Dupree, A. K.; Guinan, E. F.; Baliunas, S. L.
On November 5, 6, 1982, a luminous, flarelike brightening of the ultraviolet emissions was observed with IUE from the active RS CVn type star Lambda And during the phase of rotation period corresponding to maximum area coverage of the visible hemisphere by starspots and active regions. Enhancements during the flare in the ultraviolet emission line…
The temperature of C II emission-line formation regions in cool stars.
Carpenter, K. G.; Brown, A.
An investigation has been conducted of the temperature of C II emission-line formation regions in the outer atmospheres of late-type giant and supergiant stars. A distinct dichotomy is seen in the C II lambda 2325/lambda 1335 ratio between coronal and noncoronal stars. It is found that C II emission from noncoronal giant and supergiant stars comes…
IR Geminorum : indications of a massive white dwarf and a heated secondary in this new SU Ursae Majoris cataclysmic variable.
Szkody, P.; Shafter, A. W.; Cowley, A. P.
We report the discovery of a new SU UMa type cataclysmic variable through confirmation of a 102 minute superhump period during a supermaximum. The superhump has a 30% color-independent amplitude with a decrease in the equivalent widths of the Balmer absorption lines. Spectroscopic and photometric studies during quiescence show a 98-101 minute orbi…
An upper limit to the abundance of 9Be in the population II star HD 76932 from a high resolution spectrum with the IUE.
Molaro, P.; Beckman, J.
A high resolution spectrum (Δλ = 0.2 Å) of the Population II star HD 76932 from the archive of the IUE satellite has been analysed in a search for measurable resonance absorption lines due to 9Be. Matching the observations by a synthesized model of the wavelength region around the doublet at 3130 Å gives a conservative upper limit for t…
Cygnus X-2 : neutron star or degenerate dwarf ?
Hammerschlag-Hensberge, G.; McClintock, J. E.; Remillard, R. A. +2 more
Some conflicting models have been proposed for Cyg X-2: a degenerate dwarf model which predicts a distance of 250 + or 50 pc; and a neutron star model which implies a distance of about 8000 pc. Based on a reddening study, it is found that the distance to Cyg X-2 is greater than 1100 pc, which rules strongly against the degenerate dwarf model. This…