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The Boron Abundance of Procyon
Lambert, David L.; Edvardsson, Bengt; Lemke, Michael
The B I 2496.8 A resonance line and HST/GHRS echelle spectra are used with model atmospheres and synthetic spectra to derive the B abundance of the F dwarfs Procyon (alpha CMi), Theta UMa, and Iota Peg. The B abundance (log epsilon(B)~/=2.3) of Theta UMa and Iota Peg is similar to that derived by Boesgaard and Heacox from the B II resonance line i…
Hubble Space Telescope Imaging of Herbig-Haro Object No. 2
Schultz, A. S. B.; Raymond, John C.; Dopita, Michael A. +6 more
Images of Herbig-Haro Object No. 2 obtained with the Planetary Camera of the Hubble Space Telescope are presented and discussed. The images, obtained in the emission lines of H-alpha, forbidden S II, and forbidden O III at a scale of 0.044 arcsec/pixel, have been registered to within 11 milliarcsec, and the spherically aberrated images have been r…
Source characteristics of Jovian hectometric radio emissions
Stone, R. G.; Fainberg, J.; Reiner, M. J.
Direct confirmation that low-frequency Jovian hectometric (HOM) radio emissions centered near 0° central meridian longitude consist of distinct, oppositely polarized northern and southern beams has been achieved using data from the Unified Radio and Plasma Wave (URAP) experiment on the Ulysses spacecraft during the Ulysses-Jupiter encounter in ear…
Field-aligned currents in the Jovian magnetosphere during the Ulysses flyby
Dougherty, M. K.; Balogh, A.; Smith, E. J. +1 more
The data recorded by the dual vector helium/ fluxgate magnetometer flown onboard the Ulysses spacecraft during the flyby of Jupiter in February 1992 are analysed with the aim of identifying the presence of field-aligned current signatures. Field-aligned current flow is expected wherever stress is being transmitted electromagnetically along the mag…
A far UV investigation of luminous hot stars in the SMC cluster NGC 330.
Caloi, V.; Castellani, V.; Cassatella, A. +1 more
IUE observations of luminous blue stars in the SMC young cluster NGC 330 have been used to determine the reddening and the effective temperatures of the program objects. The reddening is estimated to be E(B - V) = 0.09 +/- 0.02, intermediate between old (~0.02) and recent (~0.12) evaluations. Stars with no recognized atmospheric anomaly show a goo…
Jovian electron propagation in three dimensions of the heliosphere: The Ulysses investigations
Balogh, A.; Smith, D. A.; Simpson, J. A. +1 more
We report investigations of Jovian relativistic electrons in the interplanetary medium that provide new insights into both the physical processes by which the Jovian magnetosphere releases its trapped relativistic electrons into the interplanetary medium, and the modes of their interplanetary propagation. These studies were dependent on the unique…
Time-variable magnetospheric radio emissions from Jupiter
Kaiser, M. L.
Jupiter is the source of a large number of independent nonthermal radio sources, all of which vary with time. The known causes of the variations include planetary rotation modulation, modulation by Io and/or its torus, and influence by the solar wind which can reach surprisingly deep into the Jovian magnetosphere. However, a significant number of …
Faint Object Spectrograph Spectra of the Broad Fe II Absorption Lines in the Remnant of SN 1006
Sarazin, Craig L.; Crenshaw, D. Michael; Fesen, Robert A. +2 more
Ultraviolet spectra of a hot subdwarf star located behind the remnant of SN 1006 have been obtained with the Faint Object Spectrograph on the Hubble Space Telescope. The FOS UV spectra show strong and extremely broad Fe II λ2343, λ2374, λ2382, λ2586, and λ2599 lines in absorption from the supernova remnant, confirming an earlier detection with the…
The ionization of the winds from cataclysmic variables without classical boundary layers.
Drew, Janet E.; Hoare, Melvin G.
We have calculated a grid of detailed photoionization models for the stellar winds in non-magnetic cataclysmic variables. In the light of evidence which questions the existence of a classical hot, luminous boundary layer we investigate (i) models with cool, luminous boundary layers or (ii) models with no boundary layer at all, but with a moderatel…
Ultraviolet-Excess Selection of the Counterpart to a Globular Cluster X-Ray Burster: Hubble Space Telescope Images of the Core of NGC 6712
Anderson, Scott F.; Margon, Bruce; Deutsch, Eric W. +1 more
Using the Planetary Camera on the Hubble Space Telescope, we have obtained high spatial resolution, multicolor images and photometry of the core of the globular cluster NGC 6712. A comparison of our blue and ultraviolet images unambiguously reveals a faint (B = 21), UV-excess object, 'star S', within the Einstein error box for the bursting X-ray s…