Search Publications
Hubble Space Telescope Observations of Synchrotron Jets
Sparks, W. B.; Macchetto, F.; Biretta, J. A.
The Hubble Space Telescope for the first time enables optical and UV images of jets to be obtained with spatial resolution comparable to radio interferometric techniques. Because synchrotron emission at these wavelengths is a diagnostic of particles several orders of magnitude higher in energy and correspondingly shorter in lifetime than those pro…
Jupiter Radio Bursts and Particle Acceleration
Desch, Michael D.
Particle acceleration processes are important in understanding many of the Jovian radio and plasma wave emissions. However, except for the high-energy electrons that generate synchrotron emission following inward diffusion from the outer magnetosphere, acceleration processes in Jupiter's magnetosphere and between Jupiter and Io are poorly understo…
Gamma-Ray Pulsar Studies with COMPTEL
Strong, A. W.; Grenier, I. A.; Diehl, R. +10 more
Since the launch of the Compton Gamma-Ray Observatory (CGRO) the number of detected gamma-ray pulsars increased from two to six. COMPTEL, on-board CGRO and sensitive to gamma-rays with energies between approximately 0.7 and 30 MeV, detected three of these unambiguously. The classical Crab and Vela pulsars have been observed on several occasions an…
A Far-Ultraviolet Atlas of Symbiotic Stars Observed with IUE. I. The SWP Range
Kafatos, M.; Michalitsianos, A. G.; Fahey, R. P. +1 more
This atlas contains sample spectra from the far-ultraviolet observations of 32 symbiotic stars obtained with the International Ultraviolet Explorer (IUE) satellite. In all, 394 low-resolution spectra from the short-wavelength primary (SWP) camera covering the range 1200-2000 A have been extracted from the IUE archive, calibrated, and measured. Abs…
Ultraviolet Spectral Classification and Stellar Winds in a Sample of Be and Standard Stars
Slettebak, Arne
Equivalent widths of 16 lines of C I, C II, C III, C IV, Si II, Si III, Si IV, Al II, Al III, Fe II, and Fe III, plus centriod and edge velocities of the Si IV and C IV lines, were measured in International Ultraviolet Explorer spectra of 39 Ble-B8e and 18 B1-B8 standard non-emission-line stars. These suggest the following: (1) Certain line ratios…
The Optical and X-Ray Content of the 1992 May 1 Gamma-Ray Burst Error Box
Cline, T.; Hurley, K.; Kouveliotou, C. +9 more
A gamma-ray burst which occurred on 1992 May 1 was observed by three spacecraft in the third interplanetary network, and rapidly localized to a small error box. The coordinates were promptly circulated to a wide astronomical community, and radio, optical, and X-ray counterpart searches were carried out. A weak X-ray source was found in the error b…
Orbits of Six Visual Double Stars
Docobo, J. A.; Ling, J. F.; Prieto, C.
New orbits have been calculated for the visual double stars WDS 04262N3443, WDS 07573N0108, WDS 08214S0136, WDS 08267N2433, WDS 19549N5049, and WDS 20232N2052 using recent observations. Dynamic parallaxes and masses have been calculated.
Gamma Rays from the Geminga Pulsar: Variations with Time and Phase
Grenier, I. A.; Hermsen, W.; Bennett, K. +5 more
Pulsed gamma radiation from the Geminga pulsar was recorded by the COS B satellite from 50 MeV to 5 GeV between 1975 and 1982. It has been analyzed to derive the source spectral properties as a function of time and phase. The two main peaks are separated by 0.50 +/- 0.01 in phase. Significant pulsed emission has also been detected in both phase re…
Observational Features of Cosmic Gamma-Ray Bursts: Evidence for Galactic versus Extragalactic Origin
Hurley, Kevin
The recent observational data on gamma-ray bursts are reviewed. Burst time histories display features at the millisecond level which suggest a compact object origin. Lines in the energy spectra and spectral evolution point toward a Galactic neutron star origin, even though line features have not yet been confirmed in recent data. The Galactic dist…
Sources and Acceleration of Energetic Particles in Planetary Magnetospheres
Moebius, Eberhard
Energetic particles in the magnetospheres of the solar system originate from various different sources, such as the solar wind, the planetary ionospheres as well as the moons and rings of the planetary systems. Important acceleration sites are the auroral regions, the magnetotail, and the equatorial regions of the magnetospheres where electric fie…