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The anomalous ultraviolet spectrum of the AM HER star H 0538+608.
Bonnet-Bidaud, J. M.; Mouchet, M.
The X-ray source H 0538 + 608, recently identified as an AM Her system, was observed with the IUE satellite and discovered to have a unique ultraviolet spectrum. The strong resonance emission lines commonly observed in the AM Her sources are present but with very unusual intensities: the C IV line is notably weak while N V strongly dominates, with…
Rotational modulation and flares on RS CVn and BY DRA stars. IV. The spatially resolved chromosphere of AR Lacertae.
Linsky, J. L.; Gary, D. E.; Walter, F. M. +4 more
The authors observed the RS CVn system AR Lacertae systematically over an orbital period with the International Ultraviolet Explorer in October 1983. Contemporaneous radio observations were obtained at the Very Large Array. The spectra of the Mg II k emission line were analyzed using a Doppler imaging technique. In this way, the authors identified…
Macroscopic Perturbations of the IMF by p/ Halley as Seen by the Giotto Magnetometer
Neubauer, F. M.; Raeder, J.; Burlaga, L. F. +1 more
Giotto magnetic field data have been used to analyze the macroscopic field structure in the vicinity of comet P/Halley. During the Giotto flyby at P/Halley the IMF showed quite a stable "away" polarity. Draping of magnetic field lines is clearly observed along the outbound leg of the trajectory. Inside the magnetic pile-up region the field reverse…
Rotational modulation and flares on RS CVn and BY DRA systems. II. IUE observations of BY Draconis and AU Microscopii.
Doyle, J. G.; Linsky, J. L.; Simon, T. +6 more
The modulation of the strong chromospheric and transition region lines over one cycle of the optical light curves of BY Dra and AU Mic is studied using IUE observations. The IUE observations were made from October 2-5, 1981 and include 7 short wavelength (SW) spectra and 13 long wavelength (LW) spectra. The integrated line flux data reveal that fo…
Rotational modulation and flares on RS CVn and BY Dra-type stars. V. EXOSAT and IUE observations of a flare on EQ Pegasi.
Doyle, J. G.; Rodono, M.; Butler, C. J. +1 more
Time-trailed UV spectra and a soft X-ray lightcurve were obtained during a flare on the binary dMe star EQ Peg AB. On the basis of solar flare Mg II surface fluxes and an about 70-percent enhancement in the disk-integrated flux during the flare on EQ Peg, it is estimated that the chromospheric flare covered about 1.5 percent of the stellar surface…
Soft X-ray observations of the radio pulsar PSR 1055-52.
Brinkmann, W.; Oegelman, H.
The radio pulsar PSR 1055-52 was observed with the EXOSAT X-ray satellite for a total of 105 s. The data can be fitted best with blackbody spectra having temperatures of 5×105 ≤ T ≤ 8×105K. The obtained temperatures are consistent with recent models for the initial cooling of neutron stars.
The pick-up of cometary protons by the solar wind
Altwegg, K.; Balsiger, H.; Goldstein, B. E. +3 more
The HERS detector of the Ion Mass Spectrometer on the Giotto spacecraft measured the 3-dimensional distribution of picked-up cometary protons over a distance of ≡8 million km upstream of the bow shock of comet P/Halley. The protons were observed to be elastically scattered out of their original cycloidal trajectories such that they were nonuniform…
Comprehensive study of the QSO-galaxy pair 1327-206 and the extent oflow ionization galactic haloes.
Kunth, D.; Bergeron, J.; D'Odorico, S.
New observations of the absorption systems in the spectrum of the QSO-galaxy pair 1327-206 are presented. At a resolving power of about 10000, the Na I doublet from the z = 0.0179 absorber is resolved in at least two components separated by 236 km s-1. The ESO 1327-2041 spiral galaxy (z = 0.0180) is at a projected distance of 20(50/H
Low-frequency magnetic field fluctuations in comet P/Halley's magnetosheath - Giotto observations
Neubauer, F. M.; Glassmeier, K. H.; Mariani, F. +1 more
The interaction region between comets and the solar wind is characterized by large amplitude, low frequency magnetic field fluctuations, both within the upstream region as well as in the magnetosheath. Magnetosheath observations of the magnetic field experiment onboard Giotto indicate values of δB/B ≅ O(1). Power spectral peaks appear at frequenci…
In-situ observations of a bi-modal ion distribution in the outer coma of comet P/Halley
Thomsen, M. F.; Wilken, B.; Feldman, W. C. +2 more
Observations obtained by the Johnstone Plasma Analyzer on the Giotto fly-by of comet Halley showed a fairly sudden decrease in the count rate of energetic (≡30 keV) water-group ions inside about 5×105km from the nucleus. This decrease was accompanied by the appearance of a new water-group ion population at slightly lower energies (<1…