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Lanning 10 and 33 : the X-ray, uv, and optical fluxes.
Szkody, P.; Crosa, L.
UV spectra from IUE, optical spectroscopy, broad band photometry, and upper limits on the X-ray flux from Einstein are used to specify the characteristics of Lanning 10 and 33. Data on Lanning 33 are consistent with a 22,000 K Be star at a distance of 5 to 7 kpc, and Lanning 10 appears to include a F5-G0 star plus a hot component greater than 35,0…
IUE observations of four planetary nebulae.
Johnson, H. M.
Low dispersion spectra of NGC 6905 and NGC 5189 are reproduced. These are nebulae with 'O VI sequence' nuclei. Line features are identified and classified according to site in the nucleus or the nebula; their flux densities are measured above continuum and presented before and after correction for interstellar extinction. The behavior of the line …
Detection of Lyman continuum absorption in the BL Lacertae object PKS0735+178.
Huggins, P. J.; Bregman, J. N.; Glassgold, A. E.
The detection of the Lyman edge in the BL Lac object PKS 0735+178 at the absorption red shift determined by optical measurements leads to a lower limit for the column density of atomic hydrogen, N(H I) not less than 4(17)/sq cm. The Lyman-alpha absorption line appears to have been detected, but only an approximate upper limit can be obtained from …
The abundance of carbon in HU 2-1.
Lutz, J. H.
A logarithmic carbon abundance of 8.61 + or - 0.3 is derived for the planetary nebula Hu 2-1 using data taken with the International Ultraviolet Explorer satellite. This value is close to the logarithmic carbon abundance of 8.67 + or - 0.1, found for the sun by other investigators. The carbon abundance of Hu 2-1 is compared to those of other plane…
Line formation in the wind of alf Cyg.
Praderie, F.; Kunasz, P. B.
In the considered investigation, the method reported by Mihalas et al. (1976) is used to search for plausible atmospheric models for Alpha Cyg and to find limits on its mass-loss rate. Assumptions about the wind and underlying photosphere, and the free parameters of the model are described. The best-suited numerical method is discussed and possibl…
IUE observations of mass ejection by the close binary system AO Cas.
Kondo, Y.; McCluskey, G. E.
It is noted that 11 high-resolution spectra in the far-ultraviolet and two high-resolution spectra in the mid-ultraviolet were obtained. A high-velocity stellar wind exists as indicated by narrow shortward-displaced absorption features superposed on the P Cygni lines of N V, Si IV, and C IV. Absorption lines caused by N IV and C III are present an…
HR 4511 : a probable cepheid with a supergiant-like hot companion.
Parsons, S. B.
IUE observations have shown HR 4511 to have an early B-type companion with a strong stellar wind. Fitting the energy distribution of the system from far-UV to middle-IR yields a difference of about 3.2 mag at the V passband. Since HR 4511 is in the small cluster Stock 14 and has M(V) = -7.8, M(V) for the secondary is about -4.6, which is only slig…
IUE observations of eight OB stars in NGC 2244 : ultraviolet continuaand extinction.
Massa, D.; Conti, P. S.
Low-resolution IUE ultraviolet continuum observations of O and B stars in the young open cluster NGC 2244 are presented. When only relative energy distributions are considered, thereby eliminating any dependence on reddening corrections or absolute energy calibrations, it is found that the ultraviolet energy distributions of the O stars have signi…
The far-ultraviolet energy distribution of two globular cluster blue horizontal-branch stars in M 13.
de Boer, K. S.; Code, A. D.
The far-UV energy distribution of two blue horizontal-branch (BHB) stars detected in the nucleus of M13 is presented. Their continua can be characterized by a model atmosphere of an effective temperature of 15,000 to 20,000 K and log g = 4.5, and it follows that V is in the range 15.9-16.7 for these stars. Comparison with integrated photometry by …
UV observation of the nucleus of NGC 3077.
Galletta, G.; Benacchio, L.
Spectroscopic observations in the range 1200-2000 A of the Ir II galaxy NGC 3077 made with the IUE telescope using the large aperture (10 arcsec x 20 arcsec) slit in low-dispersion mode are presented. The observations show the presence of a hot stellar component (20,000-23,000 K) spatially distributed in an asymmetric way. Analysis of the slit pos…