Search Publications
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…
The first IUE observations of LMC X-1 (star 32).
Pakull, M.; Bianchi, L.
The first far UV observations of LMC X-1 (star 32) are presented. Form the UV continuum distribution the authors derive a value for the reddening towards star 32 of E(B-V) = 0.05 (galactic foreground extinction) plus 0.32 (extinction in the LMC). The dereddened stellar continuum can be reproduced by a model atmosphere with Teff = 35,000…
PHL 227 : the discovery of a new nova-like object.
Heber, U.; Koester, D.; Hunger, K.
The southern (13.5-mag) subdwarf candidate PHL 227 is found to be a nova-like object (UX UMa star). The line spectrum, both at visual and UV wavelengths, is strikingly similar to that of the well known UX UMa star V3885 Sgr. PHL 227 lies in the sky region of the Palomar Green survey. In this survey only two UX UMa stars (brighter than B = 16.2) so…
High-dispersion spectroscopy of the eclipse of epsilon Aurigae at visible and ultraviolet wavelengths.
Ferluga, S.; Hack, M.
Visual observations: The authors report some preliminary results of the study of three photographic spectrograms obtained during the ingress, totality and egress phases and compare them with one spectrogram taken before the start of the eclipse. They describe the characteristics of the "shell" spectrum which are similar to those observed during pr…
Gamma-ray emission from atomic and molecular gas at intermediate galactic latitudes
Strong, A. W.
Recent developments in the study of the correlations between gamma-rays and local gas tracers are described. COS-B data in the range between b of 10 and 20 deg are analyzed using simultaneous 21-cm and galaxy count data, in order to separate the roles of atomic and molecular gas. The new galaxy-count calibration of Strong (1983) is used, and the r…
IRAS and near-infrared observations of the Seyfert galaxies MCG 8-11-11, MKN 79 and MKN 279.
Roth, M.; Di Cocco, G.; Coe, M. J. +11 more
IRAS-pointed observations and near-infrared photometry of the Seyfert galaxies MCG 8-11-11, Mkn 79 and Mkn 279 are presented. Superimposed on a power law behaviour with α = -1.2, MCG 8-11-11 shows an excess at 25 µm which can be accounted for by black body emission at ≡200K from a dust emitting region of 73 pc or more. Mkn 79 has a single po…
Variations in the variability of RR Tel.
Manfroid, J.; Heck, A.
The visible-light periodicity of the very slow nova RR Tel is inferred to vary in cycles of 350- to 410-day periods, based on the uvby photometric data, IUE FES measurements, and AAVSO visual estimates. Besides a general increase in magnitude, the visible lightcurve is also marked by two events corresponding to sudden decreases of brightness in 19…