Search Publications
First results from the Giotto magnetometer experiment during the P/Grigg-Skjellerup encounter
Glassmeier, K. -H.; Neubauer, F. M.; Pohl, M. +9 more
The Giotto magnetic field experiment has provided the first magnetic field data on the interaction between the solar wind and a low gas production comet, P/Grigg-Skjellerup. Waves produced by ion pick-up instabilities have been observed throughout the interaction region with particularly simple waveforms at large distances and a rich phenomenology…
Spectrophotometry of Wolf-Rayet Stars. I. Continuum Energy Distributions
Massey, Philip; Vacca, William D.; Conti, Peter S. +2 more
All available low-resolution IUE spectra are assembled for Galactic, LMC, and SMC W-R stars and are merged with ground-based optical and NIR spectra in order to collate in a systematic fashion the shapes of these energy distributions over the wavelength range 0.1-1 micron. They can be consistently fitted by a power law of the form F(lambda) is app…
Ultraviolet Transitions of Low Condensation Temperature Heavy Elements and New Data for Interstellar Arsenic, Selenium, Tellurium, and Lead
Federman, S. R.; Lambert, David L.; Cardelli, Jason A. +1 more
On the Lyman-Alpha Emission of Starburst Galaxies
Valls-Gabaud, David
Nearby starburst galaxies have consistently shown anomalous Lyα/Hβ ratios. By reanalyzing the published IUE/optical observations, we show that most starbursts present a normal Lyα emission, consistent with case B recombination theory, provided extinction laws appropriate to their metallicities are used. This implies that extinction is more importa…
Observations of the Solar Wind and Cometary Ions during the Encounter Between Giotto and Comet Grigg-Skjellerup
Coates, A. J.; Winningham, J. D.; Borg, H. +6 more
The solar wind interaction with the outfiowing gas from a second comet has been recorded by the same in-situ instrumentation that was used for the comet Halley encounter m 1986. The new comet, Grigg-Skjellerup, is the smallest so far observed since the size of the interaction region is comparable with a cometary ion gyroradius Preliminary results …
A survey of low frequency waves at Jupiter: The Ulysses encounter
Tsurutani, Bruce T.; Smith, Edward J.; Balogh, Andre +1 more
We report the results of a survey of low-frequency (LF) plasma waves detected during the Ulysses Jupiter flyby. In the Jovian foreshock, two predominant wave periods are detected: 102-s and 5-s, as measured in the spacecraft frame. The 102-s waves are highly nonlinear propagate at large angles to B\searrow0 (typica…
The EXOSAT Medium Energy (ME) Sample of Dwarf Novae
Mukai, K.; Shiokawa, K.
We present our analysis of the EXOSAT medium energy (ME) archival data on dwarf novae. Many dwarf novae were observed with EXOSAT; unfortunately, a significant fraction resulted in nondetection or marginal detection with the ME instrument. Our analysis of the brightest dwarf nova, SS Cyg, shows little correlation between the count rate and the har…
Optical/UV counterpart of the supersoft transient X-ray source RX J0513.9-6951 in the Large Magellanic Cloud.
Motch, C.; Bianchi, L.; Pakull, M. W. +5 more
Optical and IUE observations of the ROSAT X-ray transient RX J0513.9-6951 show this object to be remarkably similar to Cal 83, the prototype of luminous supersoft sources which is also located in the LMC. The counterpart is a B ~ 17 mag blue star which apparently did not vary much around the time of the X-ray outburst. Spectrophotometry reveals na…
The ion population between 1300 KM and 230000 KM in the coma of comet P/Halley
Altwegg, K.; Balsiger, H.; Geiss, J. +6 more
During the encounter of the spacecraft Giotto with Comet Halley the two sensors of the ion mass spectrometer (IMS), high energy range spectrometer (HERS) and high intensity spectrometer (HIS), measured the mass and the three-dimensional velocity distributions of cometary ions. HIS looked mainly at the cold, slow part of the distribution close to t…
A Hubble Space Telescope Planetary Camera View of Giant H II Regions: The Wolf-Rayet Content of NGC 595 and NGC 604 in M33
Drissen, Laurent; Moffat, Anthony F. J.; Shara, Michael M.
We present images of NGC 595 and NGC 604, the most massive giant H II regions in M33, obtained with the Planetary Camera aboard the Hubble Space Telescope in order to study their Wolf-Rayet (WR) population. Fourteen WR and/or Of candidates are detected in NGC 604, and eleven in NGC 595. All previously claimed "superluminous" WR stars are found to …