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Mass Distribution and Evolutionary Scheme for Central Stars of Planetary Nebulae
Heap, Sara R.; Augensen, Harry J.
The authors report on a study to determine the mass distribution and evolutionary scheme for planetary nuclei. First, absolute magnitudes were derived from ultraviolet stellar magnitudes for 68 galactic planetaries and three planetaries in the Magellanic Clouds. By comparing the luminosities and ages since the formation of the nebula with evolutio…
Anomalous Dust in the Open Cluster Trumpler 37
Fitzpatrick, Edward L.; Clayton, Geoffrey C.
New IUE data were obtained towards stars in the open cluster Trumpler 37. Extinction curves derived from these data show that the anomalous dust detected towards HD 204827 and HD 210072 is not unique to those lines of sight but occurs generally in that region of the sky. The dust is apparently associated with the Trumpler 37 cluster, which forms t…
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…
Extinction and Abundance Properties of Alpha Scorpii Circumstellar Grains
Buss, Richard H., Jr.; Snow, Theodore P., Jr.; Gilra, D. P. +1 more
The authors have investigated the ultraviolet extinction and element depletions in the circumstellar envelope of the M supergiant binary system, α Sco, by using IUE, Copernicus, and ANS data of the B dwarf companion, α Sco B, which can be seen in absorption through the cool-star envelope. After assessing the interstellar, circumstellar, and atmosp…
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
The Ultraviolet Spectra of Intermediate-Redshift Quasars. II.
Huggins, P. J.; Kinney, A. L.; Bregman, J. N. +1 more
This paper completes the analysis of an IUE survey of intermediate-redshift QSOs for which the results on Ly-alpha and continuum properties were given previously. The weaker lines were measured and are discussed in the context of an extended sample including Seyfert galaxies and high-redshift QSOs. The EW(C IV) anticorrelates with the luminosity o…
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…