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Impulsive bursts of relativistic electrons discovered during Ulysses' traversal of Jupiter's dusk-side magnetosphere
Simpson, J. A.; McKibben, R. B.; Zhang, M.
During its flyby of Jupiter in February 1992, the Ulysses spacecraft passed through the Southern Hemisphere dusk-side Jovian magnetosphere, a region not previously explored by spacecraft. Among the new findings in this region were numerous, sometimes periodic, bursts of high energy electrons with energies extending from less than 1.5 MeV to beyond…
Environment dependence of interstellar extinction curves.
Greenberg, J. M.; Jenniskens, P.
The IUE interstellar extinction curves published by Aiello et al. (1988) are decomposed into a bump, linear rise and FUV non-linear rise, in the parameterization scheme of Fitzpatrick & Massa (1990). The parameters of the 115 extinction curves are given. The lines of sight are characterized from the IRAS Skyflux and Point Source Catalogue data…
Dust particle impacts during the Giotto encounter with comet Grigg-Skjellerup
Colangeli, L.; Green, S. F.; Greenberg, J. M. +7 more
IN the European Space Agency's 1992 Giotto Extended Mission, the Dust Impact Detection System operated successfully during a fly-by that took the spacecraft within about 200 km of the nucleus of comet Grigg-Skjellerup. During the encounter, three meteoroid impacts were detected on Giotto's front shield. The particle masses were found to be lOO
Two New Extremely Iron-rich Hot DA White Dwarfs and the Nature of the EUV Opacity
Werner, K.; Dreizler, S.; Barstow, M. A. +8 more
We have obtained IUE echelle spectra of two bright extreme ultraviolet (EUV) sources discovered by the ROSAT wide field camera all-sky survey. These stars, RE 2214-492 and RE 0623-377, are previously uncataloged hot DA white dwarfs with respective apparent visual magnitudes of 11.71 and 12.09 and exhibit short-wavelength EUV cutoffs steeper than m…
Detection of the local interstellar cloud from high-resolution spectra of nearby stars: Inferences on the heliospheric interface
Ferlet, R.; Vidal-Madjar, A.; Lallement, R. +1 more
High-resolution spectroscopic observations of the local interstellar medium between the Sun and nearby stars have been recorded with the Aurelie spectrometer of the Observatoire de Haute Provence (France). They have been used to identify and characterize the local interstellar cloud (LIC) in which the Sun is embedded. The ``Doppler triangulation''…
Gravitational Lensing Statistics Based on a Large Sample of Highly Luminous Quasars
Magain, P.; Filippenko, A. V.; Surdej, J. +6 more
Results on gravitational lensing statistics applied to a sample of 469 highly luminous quasars are reported. The objects were directly imaged, either from the ground (ESO, CFH) under optimal seeing conditions, or using the Hubble Space Telescope. We have derived values for the effectiveness parameter F of galaxies, modeled by means of singular iso…
New light on UU Sagittae.
Pollacco, D. L.; Bell, S. A.
New V- and I-band CCD photometry and medium-resolution spectroscopy are used to derive the masses and radii accurate to less than 10 percent for the individual components of the eclipsing central star of the planetary nebula Abell 63 - UU Sge. Emission lines from the secondary component and He II and N V absorption features from the primary compon…
Analysis of the DA white dwarf HZ 43A and its companion star.
Werner, K.; Jordan, S.; Barstow, M. A. +3 more
The DA white dwarf HZ 43 A (WD 1314+293) is analyzed based on a newly obtained optical spectrogram. We demonstrate that the derived parameters Teff = 49.000 K and log g = 7.7 are in agreement with the observed Ly-alpha line, the slope of the UV continuum, and the measured trigonometric parallax. The EXOSAT spectrograms of Paerels et al.…
Low-frequency electromagnetic plasma waves at comet P/Grigg-Skjellerup: Overview and spectral characteristics
Neubauer, Fritz M.; Glassmeier, Karl-Heinz
Large-amplitude electromagnetic plasma waves are one of the dominant features of the solar wind-comet interaction. Wave characteristics strongly depend on parameters such as the solar wind flow and Alfvén velocities and the angle between flow and interplanetary magnetic field as well as the production rate. With respect to the latter the flyby of …
Mirror modes and fast magnetoacoustic waves near the magnetic pileup boundary of comet P/Halley
Motschmann, Uwe; Neubauer, Fritz M.; Fuselier, S. A. +4 more
Large-amplitude ultralow-frequency wave structures observed on both sides of the magnetic pileup boundary of comet P/Halley during the flyby of the Giotto spacecraft have been analyzed using suprathermal electron density and magnetic field observations. Upstream of the boundary, electron density and magnetic field magnitude variations are anticorr…