Search Publications
The near-ultraviolet spectrum of the high-redshift BL Lacertae object0215+015.
Blades, J. C.; Pettini, M.; Hunstead, R. W. +1 more
Spectra of the luminous high-redshift BL Lac object 0215+015 have been obtained with the IUE from 2300 to 3150 Å and with the AAT from 3040 to 3870 Å. A total of 66 absorption lines were detected, 50 of which can be identified in the six definite and one probable redshift systems ranging from zabs = 1.254 to zabs = 1.719. Str…
EXOSAT MEDA observations of Cygnus X-3.
King, A. R.; Pounds, K. A.; Willingale, R.
Results of a continuous 30.6-hr X-ray observation of Cygnus X-3 with a large area detector are presented. These show the well known, roughly sinusoidal light curve at the 4.8-hr period, with a phase-dependent variability at short time-scales, and associated spectral behavior. The sinusoidal modulation is interpreted as due to electron scattering i…
On the outer atmospheres of hybrid stars.
Jordan, C.; Dupree, A. K.; Brown, A. +1 more
The authors discuss a variety of ultraviolet observations of four hybrid atmosphere stars, objects which exhibit both cold winds and high-temperature (transition-region) emission. New IUE data confirm that the K3 II stars ι Aur and θ Her are hybrid stars. In addition γ Aql (K3 II) is found to be another hybrid object. The analysis of the emission …
LSS 2018 : a double-lined spectroscopic binary central star with an extremely large reflection effect.
Drilling, J. S.
LSS 2018, the central star of the planetary nebulae DS1, was found to be a double-lined spectroscopic binary with a period of 8.571 hours. Light variations with the same period were observed in U, B, and V; in the wavelength regions defined by the two IUE cameras; and in the strength of the CIII 4647 emission line. The light variations can be accu…
A superoutburst of the dwarf nova EK Trianguli Australis.
Hassall, B. J. M.
Simultaneous UV and optical spectrophotometry were obtained during several stages of a superoutburst of EK TrA. The observed spectra are compared with steady disc models, built both of blackbodies or Kurucz stellar atmospheres and with optically thin contributions. Atmosphere models predict much lower mass transfer rates than blackbody models. Ass…
Long-term stability of the Io high-temperature plasma torus
Skinner, T. E.; Durrance, S. T.; Feldman, P. D. +3 more
The IUE satellite was used to monitor the UV line emission of S+, S++ and S+++ ions in the high-temperature portion of the Io plasma torus. Thirteen observations obtained over a 5 yr period from 1979 March to 1984 March show that the plasma parameters of the high-temperature portion of the torus have surprisingly s…
X-Ray Emission from Cataclysmic Variables
Mason, K. O.
EXOSAT results on cataclysmic variables are reviewed. The long continuous X-ray observations afforded by this observatory, coupled with the sensitivity of its instruments to medium energy and very low energy X-rays, have enabled the rotational and orbital X-ray light curves of these stars to be measured in unprecedented detail. Examples are given …
Simultaneous X-ray and optical observations of the X-ray dip source X1755-338.
Parmar, A. N.; White, N. E.; Mason, K. O.
Simultaneous X-ray and optical observations have been made of the 'dipping' X-ray source X1755-338 which has a dip recurrence period of 4.4 hr. A sinusoidal modulation of amplitude 0.4 mag is found in the V-band light of the 18 mag optical counterpart of the X-ray source. The period of the optical modulation is consistent with the X-ray dip recurr…
Observational studies of the symbiotic stars. III. High-dispersion IUE and H alpha observations of EG Andromedae.
Stencel, R. E.; Anderson, C. M.; Slovak, M. H. +1 more
High-dispersion IUE and optical spectra are presented for the symbiotic star EG Andromedae (HD 4174). Remarkable emission-line strength and profile variations are confirmed for the S IV, O IV, C IV, and He II ultraviolet lines as well as H-alpha. Accurate cross-correlation absorption-line velocities determined from Ti I, Ca I, and Fe I features co…
Effects of nuclear uncertainties and chemical evolution on the standard big bang nucleosynthesis
Gry, C.; Audouze, J.; Delbourgo-Salvador, P. +1 more
It is shown that consistent predictions of baryonic densities can be made only for some specific galactic-evolution models involving D and He-3: either the infall of already processed material such that D/Dp = 1/15 (where Dp is the primordial abundance of D and D is the present value) or the effect of stellar mass loss releasing D free He-3 rich m…