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An Interpretation of the Line Profile Variations in the IUE Spectrum of the Wolf-Rayet Binary gamma 2 Velorum: Erratum
Sahade, Jorge; Brandi, Estela; Ferrer, Osvaldo
An upper limit on the high-energy gamma-ray emission of VELA X-1.
Kanbach, G.; Oegelman, H.; Mattox, J. R.
The possibility of high-energy gamma-ray emission from the X-ray binary Vela X-1 was investigated by analyzing the COS-B satellite observations, using the COS-B X-ray detector for a phase coherent analysis in the search of rotational periodicity. The rotational upper limit is compared to the X-ray, TeV, and PeV fluxes reported by Chodil et al. (19…
IUE Spectra of HD 269665 (Sk -68 110), a Hot Subdwarf in the Direction of the Large Magellanic Cloud
Hill, Robert S.; Smith, Andrew M.
Comparison of high- and low-resolution IUE spectra of HD 269665 (Sanduleak -68 deg 110) show that the star is a subdwarf with a temperature in the range 30,000-50,000 K. The visual spectrum shows Balmer lines and weak He II 4686 A lines. Balmer-line width and a fit of the UV-visual flux distribution using the Blackwell-Shallis (1977) algorithm yie…
Discovery of an X-Ray Selected Optically Highly Variable Quasar
Tagliaferri, G.; Branduardi-Raymont, G.; Giommi, P. +5 more
In the course of a programme of optical identification of serendipitous EXOSAT sources we have discovered a quasar (EX0033041-2613.1, referred to here as Gepu; z = 0.67) which varied by more than 3 magnitudes between November 1985 and February 1988. We present the results of optical spectroscopy and CCD photometry of the quasar which were obtained…
COS-B views on the diffuse galactic gamma-ray emission and some point sources
Hermsen, W.
The correlation between diffuse galactic gamma rays and gas tracers is studied using the final COS-B database and H i and CO surveys covering the entire galactic plane. A good quantitative fit to the gamma rays is obtained, with a small galacto-centric gradient in the gamma-ray emissivity per hydrogen atom. The average ratio of H2 colum…
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…
A Decade of Stellar Research with IUE.
Lamers, H. J. G. L. M.
Significant variation from a 1/R2 potential in the cumulative flux determined from the Giotto Comet Halley Dust Impact Experiment.
McDonnell, J. A. M.; Alexander, W. M.; McDonald, R. A. +3 more
The Giotto Comet Halley probe successfully traversed the inner coma of Comet Halley on March 14, 1986. The Dust Impact Detection System (DIDSY) aboard the Giotto spacecraft provided the information on the dust flux, mass spectrum, and cumulative mass distribution flux in the coma of Comet Halley. Analysis of discrete pulse height data of cometary …
Perturbations of Test Mass Motion in the Schwarzschild Spacetime Using the Method of Hamilton and Jacobi.
Friedjung, M.; Andrade, A. A.
This thesis develops and applies Hamilton-Jacobi perturbation theory to describe relativistic test mass motion in the Schwarzschild spacetime. The form of Hamiltonian used is rigorously derived from the relativistic Lagrangian. A justification for other choices of Hamiltonians is also given. The results of all the intermediate calculations needed …
Classification of IUE Spectra - a Rule Based Approach
Rampazzo, Roberto; Murtagh, Fionn; Heck, André