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Spectral evolution of nova CYG 1978.
Wolff, B.; Krautter, J.; Klare, G.
The evolution of the spectrum of Nova Cygni 1978 from the principal to the nebular stages is investigated. Spectrograms were obtained in the blue (between 3900 and 5100 A) and red (5600-6840 A) between September 13 and December 18, 1978. The principal spectrum of the nova, taken around maximum light on September 13, is found to be characterized by…
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…
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…
Detection of periodic light variations in the old nova V603 AQL (1918).
Boggess, A.; Drechsel, H.; Krautter, J. +2 more
Periodic visible light variations of the old nova V 603 Aql (1918) were detected with the Fine Error Sensor Instrument (FES) aboard the IUE satellite. Continuous observations were carried out during more than two complete cycles. The light curve shows a broad maximum and a pronounced minimum which was covered three times, and is tentatively interp…
I.U.E observations of HD 102567, the proposed optical counterpart of 4U 1145-61.
Bianchi, L.; Bernacca, P. L.
The B1V star HD 102567, proposed optical counterpart of the X-ray source 4U 1145-61, has been observed with the two SWP and LWR cameras on board the IUE satellite in the low resolution mode. Observations were carried out on October 5 and 14, 1978 both with the small and large spectrograph's slits. The flux has been calibrated by using the new inte…
The ultraviolet flux of HD 122563.
Gustafsson, B.; Gahm, G. F.; Bell, R. A. +1 more
Previous work has suggested that the very metal deficient giant stars are brighter in the near ultraviolet than are the corresponding model atmospheres. Observations of the star HD 122563 made with the IUE satellite suggest that this difference is less significant and may well be nonexistent at wavelengths less than 2700 A.
Ultraviolet observations of AM Her.
Tanzi, E. G.; Tarenghi, M.; Howarth, I. D. +3 more
Seven UV spectra (1150-3200 A) of AM Her were obtained with the low-resolution spectrometer of the IUE satellite. It is found that strong emission features appear to be superimposed on a well-defined continuum, which is fitted well by a lambda to the -2nd law. Observations are compared with expectations from models of the source.
High dispersion EUV observations of planetary nebulae.
Wehrse, R.; Koeppen, J.
The three high-excitation planetary nebulae NGC 3242, NGC 7009, and NGC 6210 have been observed by the IUE satellite in the 1190-1930 A wavelength range using the high resolution mode. The most prominent emission lines are the He II 1640 A and C III 1909 A lines. The C IV 1550 A lines of NGC 3242 and NGC 7009 are in emission but weaker than in NGC…
The ultraviolet high-resolution spectrum of Feige 86.
Hack, M.
The high-resolution far-ultraviolet spectrum of the halo Bp star Feige 86 is studied. The energy distribution gives T(e) between 17000 and 18000 K and log g between 4 and 4.5. 1640 He II is mainly He-3. The resonance lines of NV, CIV, SiIV are present and show three components each: one shortward-shifted by about 1.5 A and one longward-shifted by …
BD +33 2642 : a galactic halo blue star observed by IUE.
Franco, M. L.; Stalio, R.
IUE observations of the high luminosity Population II blue star BD plus 33 deg 2642 have been obtained at high resolution in the short wavelength range. The star lies at a distance of 8 kpc and has a galactic latitude plus 51 deg. The stellar spectrum shows the effect of mass loss in the highly ionized resonance lines of C IV, Si III, and Si IV. A…