Search Publications
Ultraviolet observations of hot stars with circumstellar dust shells.
Savage, B. D.; Sitko, M. L.; Meade, M. R.
Absolute fluxes over the wavelength range 1200-3200 A are presented for 13 normal early-type stars and 12 early-type stars known to have large IR excess; the data were obtained to study the UV spectral modifications produced by absorbing circumstellar dust particles. It is found that all the Be/shell stars whose spectral types are later than B6 ex…
Nova Cygni 1978 - I. The nebular phase.
Snijders, M. A. J.; Seaton, M. J.; Stickland, D. J. +2 more
UV observations of Nova Cygni 1978 have been obtained using IUE on 17 dates between 1978 September 12 and 1979 July 8 inclusive. The discussion includes the interpretation, during the nebular stage, of the UV observations together with optical and IR data from other observers. Analysis of the available data indicates that Nova Cygni 1978 was produ…
Detailed observations of NGC 4151 with the IUE. I. Low dispersion data up to 1979 january.
Tanzi, E. G.; Tarenghi, M.; Perola, G. C. +12 more
Low resolution ultraviolet spectroscopic monitoring of NGC 4151, the brightest Type 1 Seyfert galaxy, with the IUE from February, 1978 to January, 1979, is presented. Data acquisition and reduction are described. Observations were made at seven different epochs. Optimum exposure times, when the object is bright, were found to be 25-30 min and 50-6…
Ultraviolet spectra of planetary nebulae. III. Mass loss from the central star of NGC 6543.
Lutz, J. H.; Seaton, M. J.; Castor, J. I.
An ultraviolet spectrum of the central star of NGC 6543 has been obtained at low dispersion with the short wave camera of the IUE satellite, and the terminal velocity of the stellar wind has been estimated at 2150 km/s. By assuming the effective temperature to be the Zanstra temperature of 43,000 K and the luminosity to be that derived from the ev…
The nearby interstellar medium
Frisch, P. C.
The high dispersion spectrometer on board the International Ultraviolet Explorer (IUE) satellite was used to observe interstellar absorption lines in Rasalhague (α Oph). This star is located 18 pc from the Sun in the direction of the North Polar Spur, a prominent radio continuum feature in the Ophiuchus region of the sky. The satellite results, co…
Coordinated X-ray, ultraviolet and optical, observations of AM Her, UGem and SS Cyg.
Branduardi-Raymont, G.; Fabbiano, G.; Raymond, J. +3 more
Simultaneous and quasi-simultaneous optical, UV and X-ray observations of the accreting degenerate dwarf stars AM Herculis, U Geminorum and SS Cygni are reported. The observations were obtained in March 1979, by instruments on board the Einstein Observatory and the IUE satellite, and optical properties were monitored on the ground. AM Her was foun…
IUE spectroscopy of cataclysmic variables.
Vogt, N.; Wolf, B.; Krautter, J. +4 more
The continuum flux distribution and line spectra of six cataclysmic variables detected by the IUE are studied. The spectrophotometry with intermediate spectral resolution around seven A allows derivation of extinction values, temperatures, and the sizes of the radiating areas. V603 Aql, RRpic, HRDel, and TT Ari, which have similar absolute dimensi…
Extragalactic H II regions in the UV : implications for primeval galaxies.
Terlevich, R.; Meier, D. L.
Three extragalactic regions of rapid star formation with redshifts great enough to separate the Lyman-alpha region from geocoronal Lyman-alpha have been observed with the IUE satellite. Only the low metal abundance object had detectable Lyman-alpha emission with Lyman-alpha/H-alpha of about 6; the other two have Lyman-alpha/H-alpha less than 0.6 (…
Outer atmospheres of cool stars. VIII. IUE observations and chromospheric models for the supergiant stars beta Draconis, epsilon Geminorum and alpha Orionis.
Eriksson, K.; Linsky, J. L.; Basri, G. S.
A semiempirical modeling of stellar chromospheres is extended to late-type supergiants, where computations match high-resolution, absolute-flux profiles of the Ca II K and Mg II h and k lines. IUE UV spectra of Epsilon Gem and Alpha Ori show no evidence of emission lines formed at temperatures greater than 10,000 K, leading to the computation of c…
Search for gamma-radiation from extragalactic objects using a likelihood method.
Bignami, G. F.; Hermsen, W.; Masnou, J. L. +5 more
A search through COS-B data for gamma-radiation from a number of extragalactic objects reveals no strong evidence for any positive identification except, as already reported, for the region around the quasar 3C273. Upper limits to the photon fluxes from active extragalactic objects are evaluated using a likelihood method. They reinforce the conclu…