Search Publications
Ultraviolet spectral evolution and heavy element abundances in nova Coronae Austrinae 1981.
Williams, R. E.; Truran, J. W.; Wyckoff, S. +3 more
Nova CrA 1981, a moderately fast galactic nova, was systematically observed over a period of seven months with the IUE satellite. The initial evolution of the UV spectrum was similar to that of previously observed novae; however, several months after maximum, weak emission due to very high ionizating forbidden lines of Na, Mg, Al, and Si appeared,…
IUE observations of beta Pictoris : an IRAS candidate for a proto-planetary system.
Kondo, Y.; Bruhweiler, F. C.
The authors have obtained new IUE observations of β Pic, which was identified from IRAS observations as one of the several candidate stars associated with proto-planetary systems (reported by Aumann and colleagues) and whose near-infrared imagery by Smith and Terrile showed an edge-on disk surrounding the star. New high-resolution spectra, when co…
Interstellar dust in the Large Magellanic Cloud.
Martin, P. G.; Clayton, G. C.
This paper presents extensive observations of the properties of interstellar dust in the Large Magellanic Cloud. Extinction and polarization analysis of 12 reddened stars spread across the LMC shows that in the optical and infrared the dust characteristics are remarkably similar to the Galaxy. The wavelength dependence of the polarization and the …
TT ARIETIS : the low state.
Szkody, P.; Shafter, A. W.; Bond, H. E. +3 more
A comprehensive photometric and spectroscopic study of the low state of the novalike variable TT Ari has been made with observations spanning the UV to IR spectral regions. The roughly 5 mag drop in the system's luminosity from the high state indicates that the mass-transfer rate decreased by more than two orders of magnitude. The drastic reductio…
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…
The gamma-ray deficit toward the Galactic Center.
Hermsen, W.; Bloemen, J. B. G. M.; Blitz, L. +1 more
The gamma-ray flux (E greater than 300 MeV) from the central few hundred parsecs of the Milky Way is shown to be nearly an order of magnitude smaller than the value expected from the H2 masses generally estimated to be present in the center and from the average gamma-ray emissivity measured for the disk. This result implies that in the Galactic ce…
The ultraviolet spectrum of the companion of Mira (omicron Ceti) : observational evidence for a disk formed by wind accretion.
Reimers, D.; Cassatella, A.
The authors present extensive IUE observations of the companion of Mira (ο Cet B). It is shown that the UV continuum observed with IUE is exclusively due to Mira B at Mira A minimum. The UV continuum appears to vary erratically with a total range of ±30% within days or weeks. The white dwarf companion of Mira A itself is not seen and must be coole…
Ultraviolet spectra of the central stars of large planetary nebulae.
Feibelman, W. A.; Kaler, J. B.
The authors have examined the ultraviolet spectra of 32 planetary nebula nuclei with the IUE. Almost all the nebulae are quite large, with radii greater than 0.2 pc, and all are hot, with Zanstra temperatures ≥70,000K. In most cases, the fluxes at 1500 Å are closely consistent with the visual magnitudes and the assumption of a hot blackbody. The a…
Continuous rapid X-ray variability and spectral changes in NGC 4051.
Elvis, M.; Watson, M. G.; Lawrence, A. +1 more
The observation of rapid X-ray variability in active galaxies is of great potential interest. In Seyfert galaxies, variability on a time-scale of days seems common, but fast (minutes-hours) variability is apparently very rare. In a variability survey with the HEAO-1 A2 experiment, Tennant and Mushotzky (1983) found only one object to vary on short…
Detailed observations of NGC 4151 with the IUE - IV. Absorption line spectrum and variability.
Tanzi, E. G.; Perola, G. C.; Boksenberg, A. +7 more
A detailed analysis is presented of the ultraviolet (λλ1150 - 3200 Å) absorption spectrum of the NGC 4151 Seyfert nucleus. The IUE data base consisted of high-dispersion (Δλ ≡ 0.2 Å) spectra at 5 epochs, and 137 low-dispersion (Δλ ≡ 4 - 8 Å) spectra at 31 epochs from 1978 February to 1980 May, together with further low-dispersion data in 1980 - 81…