Search Publications
Search for transition zone lines in early dwarf A stars.
Freire Ferrero, R.
The presence of hot external atmospheric layers in some A stars, demonstrated by the X-ray detections with the Einstein satellite, stimulated the search for optical counterparts, in particular, the search for the UV transition zone indicators like Si IV, C IV and He II lines. The observations of a sample of early dwarf A stars with IUE allows one …
The first near-UV observation of P/Halley
Ip, W. -H.; Bertaux, J. L.; Wallis, M. K. +9 more
Comet Halley was observed on April 1, 1985 with the long wavelength camera of the IUE observatory. There is some indication that an OH emission was present at ≡3085 Å. This emission would correspond to an OH production rate of about a few 1028 molecules per second.
Search for ultraviolet emission lines from a hot gaseous halo in the edge-on galaxy NGC 4244.
Bowyer, S.; Deharveng, J. M.; Joubert, M. +2 more
Short and long wavelength IUE spectra of the halo region in the edge-on galaxy NGC 4244 are analyzed in order to identify evidence of line emission at the level of 0.000001 ergs per cu cm sr/s. Features are found at 1245 A and 1402 A, having peaks four times greater than the rms intensity fluctuations of nearby spectra. The spectral features are i…
The nitrogen abundance in Wolf-Rayet WC stars.
Schmutz, W.; Nussbaumer, H.
In order to confirm the presence of nitrogen in WC stars, the IUE spectra of the WC 8 star HD 192103 have been studied in the region 1230-1250 A. The fluxes in the spectra of HD 192103 were extracted using two different procedures: the method described by Ramella et al. (1983); and the background correction method of Schmutz (1985). It is demonstr…
The ultraviolet IUE spectrum of the population II horizontal-branch Astar HD 109995.
Leckrone, D. S.; Adelman, S. J.
Eight SWP and six LWP high dispersion IUE images of the field horizontal-branch A star HD 109995 have been averaged to increase the signal-to-noise ratio. The line density in the ultraviolet is greater than that of the optical region, but less than that of comparable Population I A stars. Many of the identified lines are those of Fe II. Lines of C…
In-flight analysis of IUE cross-disperser scattered light
Feldman, P. D.
The scattered light properties of the IUE (International Ultraviolet Explorer) cross-disperser gratings are investigated using in-flight data of the emission spectrum of Comet Bradfield (1979X). The scattering function in the vicinity of H I Lyman alpha at 1216 angstroms is found to be significantly lower than that derived from either the laborato…
The visible and infrared extinction law and the gas-to-dust ratio in the Small Magellanic Cloud.
Bouchet, P.; Lequeux, J.; Prevot, L. +2 more
Photometric observations in the UBVJHK bands have been made for 23 O-B3 stars in the Small Magellanic Cloud, for which the MK spectral type and luminosity class have been determined. Also derived from these data are the extinction curve in the visible and the near-infrared. This curve is very close to the curves in the Galaxy and the Large Magella…
The hybrid spectrum of the LMC hypergiant R 126.
Stahl, O.; Leitherer, C.; Zickgraf, F. -J. +2 more
An extensive spectroscopic (1150 - 6700 Å) and photometric (UBVRIJHKLMN) study of the peculiar LMC hypergiant R126 has been carried out. The authors derive stellar parameters Teff = 22,500K, R = 72 R_sun; and Mbol = -10.5. The corresponding spectral type is B0.5 Ia+. An estimate of the initial and present mass lead…
An X-ray study of AM Herculis. I. Discovery of a new mode of soft X-ray emission.
Stella, L.; Heise, J.; King, A. R. +4 more
The discovery of a new mode of soft X-ray emission of the magnetic cataclysmic variable AM Her is reported. AM Her has been observed in June, August and September 1983 with EXOSAT in both hard (1-30 keV) and soft (40-120 A) X-rays. Hard X-rays were seen to be partially eclipsed and periodic with the white dwarf rotation period. The eclipse phases …
UV-bright stars in galactic globular clusters, their far-UV spectra and their contribution to the globular cluster luminosity.
de Boer, K. S.
Ultraviolet-bright stars in 7 galactic globular clusters have been observed with 4 - 7 Å spectral resolution between 1150 Å and 3200 Å. The UV-bright stars, which are in the post-AGB (PAGB) phase of evolution, have effective temperatures between 19,000 and 35,000K, and have luminosities of about 103.3L_sun;. They generate on average abo…