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The first near-UV observation of P/Halley

Ip, W. -H.; Bertaux, J. L.; Wallis, M. K. +9 more

Comet Halley was observed on April 1, 1985 with the long wavelength camera of the IUE observatory. There is some indication that an OH emission was present at ≡3085 Å. This emission would correspond to an OH production rate of about a few 10²⁸ molecules per second.

Evolution of the chromospheric and coronal activity of intermediate mass stars

Brown, Alexander

Recent ultraviolet and X-ray observations pertaining to the outer atmospheric structure of intermediate mass (4-6 M₀) stars and the evolution of their structure are presented. A distance-limited (d <= 200 pc) IUE ultraviolet survey of early K bright giants shows that C IV emission commonly is present. These stars are almost evenly sp…

HD 47755, a new eclipsing binary.

Koch, R. H.; Hrivnak, B. J.; Pfeiffer, R. J. +2 more

The IUE spectra of the close binary star HD 47755 have been examined in order to determine its geometry, chemical composition, and light curve. UBV fluxes in the spectra, when dereddened for E(B-V) = 0.09 yield an effective temperature of 16,500 K. The ratio of the mean radii of the stars is found to agree well with an old blueband spectrophotomet…

X-ray Spectral Formation in Low Mass X-ray Binaries

White, N. E.

The spectral properties of the non-pulsing low mass X-ray binaries are reviewed using recent EXOSAT observations. The spectra of the persistent emission from a sample of the lower luminosity, 10³⁷erg/s systems (usually X-ray burst sources), are well modelled by a simple power law attenuated at high energies by an exponential cutoff. The…

Scattered light in the IUE spectra of epsilon Aurigae.

Kondo, Y.; Stencel, R. E.; Chapman, R. D. +1 more

Recent infrared photometry indicates that the alleged disk of particulate matter surrounding the mysterious secondary object in the Epsilon Aur system is cold, around 500 K. IUE spectra, on the other hand, contain significant flux in excess of that expected from an F0 Ia star in the far UV, which if interpreted as a hot secondary star leads to a p…

The Ultraviolet Spectrum of Procyon. I. The Atlas from 2030 to 2371 Angstrom

Kondo, Y.; van der Hucht, K. A.; Castelli, F. +2 more

The high-resolution ultraviolet spectrum of Procyon (F5 IV-V) in the range 2030-2371 A is analyzed by using BUSS VIII and IUE data. A detailed identification is performed with the synthetic spectrum method. The theoretical spectrum has been computed with a Kurucz blanketed model, and using an extended and updated version of the Kurucz and Peytrema…

Search for ultraviolet emission lines from a hot gaseous halo in the edge-on galaxy NGC 4244.

Bowyer, S.; Deharveng, J. M.; Joubert, M. +2 more

Short and long wavelength IUE spectra of the halo region in the edge-on galaxy NGC 4244 are analyzed in order to identify evidence of line emission at the level of 0.000001 ergs per cu cm sr/s. Features are found at 1245 A and 1402 A, having peaks four times greater than the rms intensity fluctuations of nearby spectra. The spectral features are i…

The Element Composition of Comet Halley Dust Particles - Preliminary Results from the VEGA PUMA Analyzers

Bertaux, J. L.; Kissel, J.; Managadze, G. G. +12 more

Ultraviolet interstellar lines towards nearby fast rotators: ZnII distribution and MgII/MgI ratios

Molaro, P.; Beckman, J. E.; Centurion, M. +1 more

We present the column density distribution of the LISM towards a sample of 15 fast rotators observed with IUE at high resolution. The targets are closer than 200 pc and most of them have lines of sight not previously investigated. Hydrogen column densities are inferred using zinc, known to be little depleted. The results are in general agreement w…

Giotto observations of the bow shock at Comet Halley

Winningham, J. D.; Thomsen, M.; Borg, H. +8 more

Preliminary results from the JPA instrument on Giotto indicate that Comet Halley, even on the flanks, has a bow shock which moves backwards and forwards over the spacecraft. To understand the structure properly will require more detailed investigation of the relationships between three particle populations, cometary ions, solar wind ions and elect…