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IUE Investigation of Mass Flow in the Interacting Binary U Sagittae

Kondo, Yoji; McCluskey, George E., Jr.; McCluskey, Carolina P. S.

Fifteen far-UV and 13 mid-UV high-resolution spectra of the interacting Algol-type binary U Sagittae have been obtained with the IUE satellite. The resonance lines of Si IV and C IV are present in absorption of moderate strength at all phases. At several phases, weak absorption due to the N V resonance lines is present. The high-temperature pseudo…

Objectives of ground-based astrometry after HIPPARCOS

Kovalevsky, J.

After a short summary of the results expected from the HIPPARCOS mission, the author gives several examples illustrating the needs that will arise afterwards in order to maintain the level of precision achieved and to extend it to many more objects. Three domains are particularly dealt with in this paper:The maintenance of the HIPPARCOS reference …

The First Year With the Hubble Space Telescope

Maran, S. P.; Kinney, A. L.

supports many very significant scientific investigations during its early orbital operations, despite the limitations imposed by an unexpected spherical aberration in the primary mirror. These early results, gathered primarily with the HST cameras and spectrographs, are reviewed, with emphasis on extragalactic, stellar, and nebular astronomy.

Far ultraviolet spectrophotometry of BD +28 4211

Green, James C.; Cook, Timothy A.; Cash, Webster

We report the results of a November 1989 rocket flight which recorded a flux calibrated spectrum of BD +28 4211 from 912 to 1150Å with 1Å resolution. BD +28 4211, an SdO type star, is commonly used as an ultraviolet calibration source in the IUE wavelength band. Our work extends the useful range of this standard shortward of Lyman α. Since previou…

Location and thickness of the nearest neutral gas cloud in the direction of Auriga-Perseus.

de Boer, K. S.; Lilienthal, D.

High dispersion IUE spectra of stars in the general direction of Auriga-Perseus show clear interstellar absorption lines whose strengths are used to derive information about the spatial distribution of the gas on the lines of sight. The distance to the nearest neutral cloud in this direction is about 50 pc; it has a depth of approximately 15 pc an…

The variable energy-distribution of the gamma-ray emission from Geminga

Grenier, I. A.; Hermsen, W.; Hote, C.

The gamma-ray emission of Geminga during five COS-B observations has been analysed to derive its spectral properties between 50 MeV and 5 GeV. In all observations but one, the spectrum presents a turnover between 100 and 200 MeV, the source becoming very weak at the lowest gamma- ray energies. During the remaining observation, the spectrum is cons…

The nature of HD 220140 from optical and IUE observations.

Bianchi, L.; Fekel, F. C.; Jurcsik, J.

Results are reported from photometric observations of the optical counterpart of H2311 + 77 that Pravdo et al. (1985) suggested to be a new RS CVn star. The claim of Poretti et al. (1985) of a photometric period of 0.5767 days for this object is disproved by the data obtained. Observations with the IUE satellite at different phases of the light cu…

Spectroscopic binary orbits from ultraviolet radial velocities. Paper 7: V861 Scorpii (HD 152667)

Howarth, I. D.; Stickland, D. J.

The peculiar UV and optical spectrum of the LMC supergiant HD 269216.

Prinja, R. K.; Schild, H.

Low resolution IUE UV and optical observations are presented of HD 269216, the visually brightest member of the LH 39 association in the LMC. Although the UV and optical line spectra are broadly consistent with a B 8 Ia spectral type for HD 269216, the classification is complicated by several discrepancies. The observed UV continuum flux distribut…

The Ultraviolet Spectrum of KX Trianguli Australis

Feibelman, Walter A.

Low-dispersion and high-dispersion IUE satellite observations of the symbiotic star KX TrA, carried out on May 7, 1990, are reported. The low-dispersion data show no significant changes from the observation data obtained a decade ago. Resonantly excited high-excitation Fe II emission lines are seen in the UV spectra of KX TrA, suggesting the exist…