Search Publications
The High-Luminosity BL Lacertae Object PKS 0823-22
Falomo, Renato
Simultaneous infrared, optical, and UV observations of the BL Lacertae object PKS 0823-22 are presented. The identification of the observed absorption doublet at λλ5341, 5355 with Mg II λλ2796, 2803 gives an absorption redshift z_abs_ = 0.910. At this redshift, the object is one of the most luminous of its class with M_V_ <~ -29.4. The spectral…
Detection of Trace Helium in G104-27, a 26,000 K DA White Dwarf
Wesemael, F.; Holberg, J. B.; Kidder, K. M.
The detection of the He I 4471 A feature in the moderately hot DA white dwarf G104 - 27 places this star within the rather sparse class of DAB white dwarfs. It does not appear possible, on the basis of the present data, to distinguish between a stratified and a homogeneously mixed atmosphere. While a stratified structure would be natural for a DA …
EXOSAT observation of the supernova remnant MSH 15-52.
Hasinger, G.; Aschenbach, B.; Brinkmann, W. +3 more
The results of an Exosat observation of the supernova remnant MSH 15-52 and of the pulsar PSR 1509-58 are presented and discussed. In the energy range 1.6-11 keV, the radiation flux of the nebula surrounding the pulsar detected by the ME instrument has been fitted with a power law spectrum with index alpha about 1.86 (photon spectrum) and column d…
IUE observations of mass-loss spectral features in B5-B9 supergiants.
Bates, B.; Gilheany, S.
A survey of IUE spectra is presented for supergiants of spectral class B5-B9 illustrating the behavior of line profiles associated with mass-loss effects. The main purpose of this survey is to better identify the spectral mass-loss features which occur in such stars in order to present a clearer observational picture of the nature and the timescal…
Hypervelocity dust particle impacts observed by the Giotto Magnetometer and Plasma Experiments
Coates, A. J.; Glassmeier, K. -H.; Neubauer, F. M. +3 more
We report thirteen very short events in the magnetic field of the inner magnetic pile-up region of comet Halley observed by the Giotto magnetometer experiment together with simultaneous plasma data obtained by the Johnstone plasma analyzer and the ion mass spectrometer experiments. The events are due to dust impacts in the milligram range on the s…
Small-Scale Structure in the Diffuse Interstellar Medium
Meyer, David M.
The initial results of a study to probe the small-scale structure in the diffuse interstellar medium (ISM) through IUE and optical observations of interstellar absorption lines toward both components of resolvable binary stars is reported. The binaries (Kappa CrA, 57 Aql, 59 And, HR 1609/10, 19 Lyn, and Theta Ser) observed with IUE have projected …
The nucleus of Abell 35 : a cataclysmic binary ?
Jasniewicz, G.; Acker, A.
Simultaneous photometric and spectroscopic observations of the visible central star BD - 22 deg 3467 of the large planetary nebula Abell 35 are reported. This fast rotating star has a spectral type G8IV, and shows a double peaked emission line at H-alpha, varying with a period identical to the photometric one, equal to 0.7653 days. Both the maximu…
Discovery of a highly ionized, low mass-loss wind and a corona seen in absorption in the G9 II star HR 6902.
Reimers, D.; Baade, R.; Schroeder, K. -P.
IUE observations of HR 6902 (G9II + B9V) 1 and 2 days before and during total eclipse of the B star are discussed. The G bright giant has a highly ionized, hot (Te = 87,000 K) wind seen as C IV, Si IV, and C II resonance-line scattering of B-star photons during totality, with a mass-loss rate of 2 x 10 to the -11th solar mass/yr (+ or - factor 3).…
A Catalogue of Low-Resolution IUE Spectra of Dwarf Novae and Nova like Stars
La Dous, Constanze
A catalogue is presented of all the low-resolution IUE spectra of dwarf novae and nova-like stars that were recorded until the end of 1987. All spectra have been reduced, and are displayed, in a homogeneous way. In addition to details about these data, to the extent available, their position in the outburst light curves is given, physical informat…
UV observations of Herbig-Haro objects associated with bipolar molecular outflows : HH 7, HH 11 and HH 29.
Liseau, R.; Cameron, M.
Results are presented of IUE observations of three shock excited visible Herbig-Haro nebulae: HH7, HH 11, and HH 29. With the possible exception of HH 11, large deviations were found from the 2 2S-1 2S two-photon decay continuum of atomic hydrogen. It was also found that the continuum of HH 29 varies considerably in both the intensity and the spec…