Search Publications
An analysis of scattered light in low dispersion IUE spectra.
Clarke, J. T.; Basri, G.; Haisch, B. M.
A detailed numerical simulation of light scattering from the low-resolution grating in the short wavelength spectrograph of the IUE Observatory was developed, in order to quantitatively analyze the effects of scattering on both continuum and line emission spectra. It is found that: (1) the redistribution of light by grating scattering did not appr…
The distribution of the local interstellar medium derived from MG II column densities towards seven cool stars.
Molaro, P.; Franco, M. L.; Beckman, J. E. +2 more
High resolution spectra containing the Mg II h and k resonance doublet have been obtained using the long wavelength spectrometer of IUE, for 7 late-type stars (F0 to G8). In one of these stars, β Hyi, two sharp absorption features were detected against the chromospheric emission cores. Using the study of Crutcher (1982) the authors can employ the …
Gas and star content and spatial distribution in the giant extragalactic H II region TOL 89.
Boksenberg, A.; Durret, F.; Bergeron, J.
Tol 89 is a giant H II region 2.5 kpc in diameter, located in one of the arms of the spiral galaxy NGC 5398. We have observed this object in the Uv with the International Ultraviolet Explorer, and at optical wavelengths with long slit spectrophotometric equipment. The UV spectrum of Tol 89 reveals P Cygni profiles, characteristic of stars with str…
Temporal variations in UV spectra of the red giant C star, TW Hor.
Querci, M.; Querci, F.
The time behavior of ultraviolet emission lines in the cool carbon star TW Hor is discussed. The emission lines were obtained over a three year period using the International Ultraviolet Explorer (IUE) spacecraft in the wavelength range 2100-3300 A. All the lines are found to vary in time (on scales of about one hour to two months) without any app…
Spectroscopy and spectrophotometry of the nova-like system V3885 Sagittarii.
Drechsel, H.; Haug, K.
New optical and UV observations of the novalike variable V3885Sgr are analyzed. The line identifications and radial velocity measurements are presented, and the Balmer, He I, and He II line profiles are investigated. Physical parameters of the system are derived, and spectrophotometric light curves are presented. The continuum flux distribution be…
The Lyman alpha emission in W Ursae Majoris.
Whelan, J. A. J.; Vilhu, O.; Rucinski, S. M.
The paper presents results of reductions of six low resolution IUE-SWP spectra properly exposed at Ly-alpha during one orbital revolution of WUMa, the prototype for late-type contact binaries. Two different methods have been used to eliminate the geocoronal contribution to the emission line. The effect of the interstellar H I absorption has been m…
C IV and SI IV in the interstellar medium.
de Jong, T.; de Kool, M.
Column-densities are presented of C IV and Si IV along the line of sight to 49 galactic O-stars, derived from IUE spectra. Since these column-densities appear to be uncorrelated with the distance to the background star a truly interstellar origin of these lines can be ruled out. The fact that large column-densities are preferentially observed towa…
Discovery of a cataclysmic variable type companion of the M3 III giant 4 DRA with IUE.
Reimers, D.
IUE observations show that the bright (mv∼5) normal M 3 III giant 4 Dra has a blue companion. Its spectrum increases to shorter wavelengths in the IUE short wavelength region and has strong emission lines of high excitation (CIV, NV, CIII, HeII, ...) superimposed. The spectrum of the companion of 4 Dra bears similarity to UV spectra of …
HD 87643 : a B E star with a cold wind.
Selvelli, P. L.; de Freitas Pacheco, J. A.; Faria Lopes, D. +1 more
Ultraviolet observations of the B/e/ star HD 87643 have revealed the presence of a wind in low ionization species with outflow velocities of up to 800 km/s in the Mg II doublet. The dominating species in the spectrum are the once-ionized metals, mostly Fe II. The P Cyg profiles of the Mg II lines have a structure similar to that of the Balmer line…
Simultaneous ultraviolet and optical observations of FK Comae.
Grewing, M.; Bianchi, L.; Kappelmann, N.
The authors report simultaneous photometric and spectroscopic observations of FK Comae. Photometric measurements were made in the UBVR system, and in two bands centered near Hα and Hβ, respectively. The spectroscopic measurements were obtained with the IUE satellite in the 1150 - 3200 Å band near phases 0 and 0.5, in order to distinguish between t…