Search Publications
Solar wind composition and expectations for high solar latitudes
Geiss, J.; von Steiger, R.
Instruments on board the Ulysses spacecraft are to investigate, for the first time, the solar wind in the three principal domains of solar latitude. (1) During Ulysses' flight in the ecliptic plane the solar wind near the current sheet was continuously measured, and its composition was determined with unprecedented sensitivity and mass resolution …
Spectroscopic binary orbits from ultraviolet radial velocities. Paper 13: HD 93205
Stickland, D. J.; Lloyd, C.
On the Chromosphere of 32 Cygni
Eaton, Joel A.
Archival IUE observations and new optical spectra of atmospheric eclipses are analyzed to define the physical properties of the chromosphere of 32 Cyg. Excitation temperatures clearly rise with height in the chromosphere, starting at about 5000 K close to the star. Temperatures in the range 12,000-17,000 K are attained high in the chromosphere, al…
Energetic particle, plasma and magnetic field signatures of a poloidal pulsation in Jupiter's magnetosphere
Dougherty, Michele K.; Balogh, André; Keppler, Erhard +6 more
During its February 1992 inbound journey into Jupiter's magnetosphere, Ulysses made several near-encounters with (and actual traversals of) the Jovian magnetodisk. In at least one such event (investigated here) the anticipated variations in energetic particle fluxes, plasma density, magnetic field intensity, and magnetic field direction at the pla…
Is the accretion disc of TT Ari hotter after a minimum ?
Pringle, J. E.; Tout, C. A.; La Dous, C.
Ultraviolet spectra of nova-like variables appear to be cooler than those of dwarf novae in outburst. This suggests that, once a steady-state accretion disc becomes established, it releases less of its energy thermally and more in other forms such as mass loss or magnetic flux. Here we use archival lUE data for the anti-dwarf nova TT Ari to show t…
The Companion of the Classical Cepheid Z Lacertae
Evans, Nancy R.; Welch, Douglas L.
A deep IUE exposure of the Cepheid Z Lac from 1200 to 2000 A has been taken in order to search for light from the radial velocity companion. A faint signal of approximately 1.0 X 10^-14 ergs A^-1 sec^-1 cm^-2 has been detected in the dereddened spectrum. Because this is approximately the flux expected due to "camera artifacts," we consider that at…
The Starburst model for the optical variability of the Seyfert 1 galaxies NGC 4151 and NGC 5548
Aretxaga, Itziar; Terlevich, Roberto
In the frame of the Starburst model, we show that the stellar processes expected to occur during the evolution of a metal rich massive stellar cluster can reproduce the observed optical light curves of the Seyfert 1 galaxies NGC 4151 and NGC 5548.
A Thick Reflection Nebula Illuminated by a Power Law
Binette, Luc; Martin, Peter; Magris C., Gladis
We present the results of modelling the energy distribution of a power law reflected by a dusty cloud. We explore in a fully consistent manner the case in which the reflecting nebula is of considerable optical depth. We apply the model to the observations of the detached emission line cloud at 8 kpc from the nucleus of Pks 2152-69 for whichcontinu…
31 Cygni: The B Star and the Wind
Eaton, Joel A.
I have followed photospheric and wind absorptions in International Ultraviolet Explorer (IUE) spectra over much of the orbit of this K4 Ib+B3-4 binary system, using interstellar lines to transform all the velocities to a scale with the interstellar medium at -10.1 km/s. Results are as follows: Interstellar Fe II lines give NL (Fe(+)) = 1-2 x 10
Hubble Space Telescope spectroscopy of massive hot stars in the Magellanic Clouds and M31
Lennon, D. J.; Bianchi, L.; Puls, J. +4 more
Using the Hubble Space Telescope (HST) and the Faint Object Spectrograph (FOS) high signal to noise spectrograms were obtained for 15 OB stars in the Magellanic Clouds***, three of which are of spectral type O3. The data cover the spectral region from 1150 A 2300 A with a resolution of Δλ/λ≈1 A. One O8.5 supergiant, OB78#231, in M31