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Analysis of the ultraviolet spectrum of RWT 152 : a subluminous O star with a main-sequence visual spectrum.
Savage, B. D.; Ebbets, D. C.
Observations of luminous early-type stars provide one of the most sensitive ways to detect the low density gas of the interstellar medium. As part of an ongoing program studying the gas in the galactic halo, stars believed to be outside the plane of the Milky Way have been observed. In the interest of studying the halo gas in additional directions…
Observations of interstellar zinc.
York, D. G.; Jura, M.
IUE observations toward 10 stars have shown that zinc is not depleted in the interstellar medium by more than a factor of two, suggesting that its abundance may serve as a tracer of the true metallicity in the gas. A result pertinent to the history of nucleosynthesis in the solar neighborhood is that the local interstellar medium has abundances th…
The ultraviolet spectrum of Herbig-Haro object 2H.
Shull, J. M.; Brugel, E. W.; Seab, C. G.
IUE spectra of Herbig-Haro object 2H are presented. The spectra show a strong 'excess' UV continuum and prominent emission lines of C, N, O, Si, Mg, and possibly Al. The continuum, F(lambda), exhibits a turnover shortward of about 1450 A, confirming for the first time the H0 two-photon nature of the emission source. A possible absorption feature n…
The chromosphere and wind of the Herbig AE star, AB Aurigae.
Talavera, A.; Czarny, J.; Felenbok, P. +2 more
The Herbig Ae variable, AB Aur, has been observed with the CFHT coudé spectrograph at 95 mÅ resolution for five consecutive nights in the blue spectral region and with the lUE satellite in the high resolution, long wavelength mode. The Ca II K line shows an asymmetric and variable profile and shows weak emission in the absorption core at least som…
IUE observations of proto-planetary nebulae. I. V1016 Cyg, HM SGE andHBV 475.
Feibelman, W. A.
The IUE satellite has undertaken UV observations of the proto-planetary nebulae V1016 Cyg, HM Sge, and HBV 475, yielding emission line fluxes, line ratios, line profiles, electron densities, and distances from these objects. While levels of increasing excitation and ionization as a function of time are shown by the data for the first two nebulae, …
An ultraviolet study of high velocity interstellar lines in the Carina Nebula.
Walborn, N. R.; Hesser, J. E.
An analysis in light of high-resolution IUE observations is presented for the interstellar absorption lines in the spectra of stars within the Carina Nebula, where complex and high-velocity profiles are known to exist from Ca II data. The high-velocity structure is found to be most pronounced in the low-ionization UV lines, and several new compone…
Ultraviolet spectrum variability of UX UMa.
Holm, A. V.; Panek, R. J.; Schiffer, F. H., III
IUE spectra show UX Ursae Majoris to be a spectacular ultraviolet line spectrum variable on time scales of months. Time-resolved spectra around the orbit show that the continuum is strongly eclipsed, whereas the line emission is not. Features in the light curve which are identified with a hot spot are not prominent in the far-UV. The UV line emiss…
The interpretation of the spectra of two magnetic degenerates
Oke, J. B.; Greenstein, J. L.
Ultraviolet and optical fluxes are measured for two magnetic degenerates, Feige 7 (Gr 267) and Grw + 70 deg 8247 (EG 129), from 10,000 to 1150 A. A method is developed for fitting blackbodies and models to this broad range of fluxes. From models, the best effective temperatures average 20% below the blackbody temperatures. Feige 7, a mixed H + He …
The ionization structure of the ring nebula. II. Ultraviolet observations.
Barker, T.
Good agreement is found for O and N abundances, and the importance of charge-transfer reactions to the ionization of Ne is confirmed, in UV observations of emission line intensities for four positions in the Ring Nebula that have been previously studied optically. It is noted that the C(2+) abundance inferred from the optical 4267 A recombination …
Ultraviolet absorption by interstellar gas near the LMC star HD 36402in the interstellar bubble N51D.
de Boer, K. S.; Nash, A. G.
Four interstellar absorption components associated with the immediate surroundings of the star are found in UV, high-dispersion IUE spectra of the LMC star HD 36402 in the N51D nebulosity. The 305 km/sec absorption is found to originate in low-density, 10,000 K gas, and the density and velocity structures agree with that derived from visual emissi…