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IUE observations of the continuous spectrum of the Orion nebula.
Patriarchi, P.; Perinotto, M.
The continuous spectrum of the Orion Nebula has been observed in two positions in the bright Huyghenian region with the IUE (International Ultraviolet Explorer) satellite with a resolution of about 7 A in the spectral range of 1150-3200 A. The illuminating stars Theta 1 Orionis C and Theta 2 Orionis A have been observed under the same conditions. …
Radial velocity study of four southern RS CVn candidates and related field stars.
Stencel, R. E.; Stacy, J. G.; Weiler, E. J.
Radial velocity variations are demonstrated for four southern RS CVn candidates: HD 39937, 101379, 155555, and 174429. The period of HD 155555 appears to have decreased by about one part in 100,000 over the past 18 yr. In addition, high-resolution observations of the Ca II H and K profiles and the Mg II 2800-A emission doublet are presented. These…
Ultraviolet observations of the blue halo star : HD 93521.
Morossi, C.; Ramella, M.; Santin, P.
The ultraviolet spectrum of the high galactic latitude O-type star HD 93521 has been studied. Interstellar and stellar features are listed, identified from IUE high resolution spectrograms. A comparison between the observed UV flux distribution obtained with the S 2/68 satellite and that derived from theoretical models by Kurucz is given. An alter…
Observations of R Aqr.
Johnson, H. M.
Observations of ultraviolet emission lines and continuum with the IUE observatory, H-alpha flux density and line profiles of H-alpha and forbidden O III lambda-5007 with the CTIO Fabry-Perot interferometer, and detection of the 85 GHz continuum with the 11 m dish of the NRAO are presented. Comments on their relation to previous work on R Aquarii a…
The UV spectrum of the narrow emission line X-ray emitting nucleus ofthe galaxy NGC 7582.
Penston, M. V.; Clavel, J.; Macchetto, F. +5 more
UV spectra of the narrow emission line, X-ray emitting nucleus of the galaxy NGC 7582 obtained with the IUE instrument show a steep featureless continuum, obeying a power-law of spectral index 3.4 + or - 0.4, close to the value of Ward et al. (1978) for the visible spectrum (spectral index equal to 3). The visual extinction on the line-of-sight of…
Long-slit spectroscopy in the rocket ultraviolet of the Orion nebula.
Bohlin, R. C.; Witt, A. N.; Stecher, T. P. +1 more
The study deals with the extensive nebulosity in the Trapezium region of Orion. An entrance slit was placed at the focal plane of rocketborne telescope, creating a long-slit spectrograph with a wavelength resolution of 22 A FWHM and a spatial resolution of 14 in. along the slit. Data reduction is outlined, the structure of the Orion Nebula is disc…
HD 15570 : a star intermediate between Of and WN7 ?
Willis, A. J.; Stickland, D. J.
IUE ultraviolet observations of HD 15570, classified in the visible as O4f, show the presence of N IV wavelength 1486 and He II wavelength 1640 strongly in emission, spectral characteristics which are signatures of WN stars rather than Of stars. A comparison of the UV spectra of this star with those of Xi Pup (O4f), HD 164794 (O4V) and HD 93131 (W…
The CIV resonance lines in B and early A supergiants.
Underhill, A. B.
A rapidly moving hot wind, with Vinfinity near 620 km/s, is seen by means of C IV resonance lines at types B2 Ia and B3 Ia. The C IV lines are not obvious in the winds from supergiants of types B5 Ia to A2 Ia. In the A0 Ia star HD 21389 the C IV lines appear sporadically as sharp, undisplaced emission lines, suggesting the sporadic pres…
IUE and balloon spectral observations of mass loss from BET Ori.
Bates, B.; Giaretta, D. L.; McCartney, D. J. +2 more
New observations are presented of the ultraviolet spectrum of Beta Ori which were obtained from the International Ultraviolet Explorer and from a high resolution, balloon-borne spectrograph. The blue-shifted, high velocity components (HVC) in the Mg II resonance lines indicate that a small deceleration of the material relative to the star has occu…
The number-intensity relation for galactic gamma-ray sources and the emission from the galactic disk
Caraveo, P.; Rothenflug, R.
The paper evaluates the contribution of unresolved gamma-ray sources to overall emission of the Galaxy starting from the data on the resolved ones listed in the 1st COS-B catalogue, covering up to 50 percent of the galactic plane. It is shown that the integral Log N (greater than S)-Log S graph of an homogeneous subject of 9 of the 13 COS-B source…