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Erratum - Detailed Observations of NGC4151 with IUE - Part Three - Variability of the Strong Emission Lines from 1978FEB to 1980MAY

Tanzi, E. G.; Tarenghi, M.; Perola, G. C. +8 more

Visual and ultraviolet spectrum of the eclipsing binary V367 Cygni.

Hack, M.; Engin, S.; Yilmaz, N.

V 367 Cyg is a single spectrum eclipsing binary (P = 18.6 d) classified as Beta Lyrae type. Spectroscopic observations during two successive cycles confirm previous studies and indicate that the shell spectrum does not vary greatly and does not present appreciable expansional velocity. The radial velocity of the shell lines may be explained by a r…

Exosat observation of the candidate X-ray counterpart of Geminga

Caraveo, P. A.; Bignami, G. F.; Mereghetti, S. +2 more

During a search for X-ray counterparts of the COS B>=100 MeV γ-ray sources (see refs 1, 2), observations using the Einstein Observatory revealed a new X-ray source, 1E0630 + 178, inside the ~1/2 square degree error box of the γ-ray source 2GC195+4, `Geminga'³. On the basis of its interesting properties, this source has been proposed …

The distribution of interstellar matter toward Tycho's supernova remnant and its relation to distance estimates.

Raymond, J. C.; Black, J. H.

Observations of interstellar absorption lines in the spectra of five stars in the direction of Tycho's Supernova Remnant are presented. The profiles show significant absorption at large negative velocities, - 50 to - 60 km/s (LSR). This information, together with the distances of the background stars, permits limiting distances to be assigned to t…

IUE observations of two extremes among contact binaries : AW Ursae Majoris and SW Lacertae.

Pringle, J. E.; Vilhu, O.; Rucinski, S. M. +1 more

The authors present IUE observations of AW UMa and SW Lac. These stars are the most extreme representatives of the A- and W-types of W UMa stars and might therefore be expected to differ most in their properties. The authors find that the stars are similar in their transition region emission (N V, C IV, Si IV) but differ markedly in their chromosp…

The UV variations of the symbiotic star CH Cygni from 1978 to 1981.

Hack, M.; Persic, M.; Selvelli, P. L.

The spectroscopic changes of CH Cygni from early 1978 to late 1981 are discussed with reference to several ultraviolet spectra obtained at the Villafranca Satellite Tracking Station. Correlations have been found to exist between the fluxes of the continuum and the fluxes of the forbidden and semiforbidden lines. Three new forbidden-line identifica…

Evolution of the ultraviolet coma of comet Austin (1982g.)

Feldman, P. D.; Keller, H. U.; A'Hearn, M. F. +6 more

Ultraviolet spectra of comet Austin (1982) obtained in July 1982 at heliocentric distances ranging from 1.10 to 0.81 AU preperihelion with the IUE reveal that the comet is very similar in chemical composition and appearance to comet Bradfield (1979X). In addition, the derived H2O production rate is found to vary with heliocentric distance as r to …

RZ Gru - a UX UMa 'disc star'.

Stickland, D. J.; Kilkenny, D.; Kelly, B. D. +4 more

The star RZ Gruis is confirmed as a cataclysmic variable. Its ultraviolet spectrum suggests that it belongs to the UX UMa subclass in which an optically thick disc is maintained at outburst state; coordinated optical and UV photometry show changes of about one magnitude on a time-scale of months in addition to smaller variations on a scale of minu…

Far-ultraviolet spectra of the nuclei of globular clusters M 30, M 54, M 70.

Wamsteker, W.; Caloi, V.; Castellani, V. +1 more

IUE spectra in the low dispersion mode have been collected from the nuclei of the three galactic globular clusters NGC 6681 (= M70), NGC 6715 (= M54), and NGC 7099 (= M30). High UV fluxes are obtained from M54 which had been found earlier to be a real characteristic of the cluster population, suggesting a possible connection of this cluster with E…

IUE observations of the "Butterfly" nebula M 2-9.

Feibelman, W. A.

IUE observations of the peculiar 'Butterfy' nebula M2-9 indicate that it is not a normal planetary nebula. The ultraviolet spectrum is characterized by few emission lines and a weak continuum. Mg II 2800 A is the strongest emission line present and may be indicative of a binary nucleus. Lines of N v, Q I, N III, N IV, Si III, and C III are seen, b…