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Ultraviolet, Optical, Infrared, and Microwave Observations of HR 5110
Linsky, J. L.; Simon, Theodore; Ayres, T. R. +5 more
HR 5110 is a close binary system (P = 2d.6) with the characteristics of an Algol system. Because the primary star is relatively cool (F2 IV) and there is no apparent emission from an accretion disk, the authors were able to detect in IUE spectra the emission of an active chromosphere and transition region of the cooler (K0 IV) secondary…
Spectrum and Chemical Analysis of the Double-Ring Planetary Nebula IC 1297
Feibelman, Walter A.; Aller, Lawrence H.; Keyes, Charles D.
The double-ring planetary nebula IC 1297 resembles NGC 7662 in appearance, although it is of much lower surface brightness. What is remarkable is the great strength of the dielectronic recombination O V line. Although this line is seen as a P Cygni feature in a number of planetary nebulae, it is in those instances accompanied by a strong continuum…
New X-Ray and Optical Observations of the X-Ray Discovered QSO-Galaxy Pair 1E 0104.2+3153
Stocke, J. T.; Giommi, P.; Maccacaro, T. +2 more
New X-ray and optical observations are presented of the QSO-galaxy pair 1E 0104.2 + 3153, originally discovered as a serendipitous source in the Einstein Observatory Medium Sensitivity Survey (Gioia et al., 1984). Results from an extremely deep Exosat observation are used to suggest that the QSO rather than the compact group of galaxies is the opt…
IUE Observations of Accretion Columns in Two Zeta Aurigae--Type Systems
Ahmad, I. A.
This paper reports the existence of an accretion column in 32 Cyg. It also confirms the presence of the accretion column in ζ Aur and reports the detection of secular variations. Mg II observations support the parameters derived by Ahmad, Chapman, and Kondo for ζ Aur but suggest that the column may be curved. A C IV and Si IV emission component is…
Ultraviolet Survey for Hot Companions among Nonvariable Yellow Supergiants
Arellano Ferro, A.; Madore, B. F.
Twenty nonvariable yellow supergiants have been observed for the first time with the International Ultraviolet Explorer satellite, with the aim of discovering hot companions. Two newly discovered systems are announced: HD 74395 (G2 I + B9.5 IV-V) and HD 193469 (later than G0 + B8 IV-V). The Cepheid HD 9250 was also observed, but no hot companion w…
Rapid X-Ray and Optical Variability in the X-Ray--selected BL Lacertae Object 1E 1402.3+0416
Giommi, Paolo; Barr, Paul; Gioia, Isabella M. +4 more
Results from X-ray and optical observations of the X-ray-discovered BL Lac object 1E 1402.3 + 0416 are presented, where the X-ray measurements were carried out with the Channel Multiplier Array (CMA) and Medium Energy experiment (ME) detectors on board Exosat. These measurements revealed an intensity decrease by a factor of two on a time scale of …
The Unusual Ultraviolet Variability of the QSO 3C 232
Kafatos, M.; Bruhweiler, F. C.; Sofia, U. J.
After examining ultraviolet IUE spectra of 18 QSOs with z greater than 0.35, it is found that one object, 3C 232 (z = 0.533), stands out as exhibiting higly unusual spectral and continuum variability. The H I-Ly-alpha shows at a factor of two decrease in a day. The magnitude of the UV continuum variability is reminiscent of that seen in the optica…
On the X-Ray and Ultraviolet Spectrum of the High-Redshift Quasar 3C 446
Tagliaferri, G.; Garilli, B.
Existing IUE and Einstein observations of the high-redshift (z = 1.414) quasar 3C 446 have been analyzed. In the UV the continuum is characterized by a steep slope. The lack of signal shortward of 2300 Å is probably due to the Lyman continuum absorption at the source. The X-ray spectrum shows the "universal" slope of active galactic nuclei coupled…
Colors of Reflection Nebulae. III. Ultraviolet Scattering by Small Particles in Reflection Nebulae Associated with 17, 20, and 23 Tauri
Bohlin, R. C.; Witt, A. N.; Stecher, T. P.
New surface brightness measurements in the reflection nebulae associated with the Pleiades stars 17, 20, and 23 Tau have been carried out with the IUE satellite. Each nebula was observed at two angular offsets south of the respective illuminating star. At the larger offsets (40, 40, and 60 arcsec respectively) each nebula exhibits a flux distribut…
EXOSAT and Einstein X-Ray Observations of the SNR 1E 1149.4-6209 in Crux: A Unified Picture?
Caraveo, P. A.; Bignami, G. F.; Mereghetti, S. +2 more
New EXOSAT and Einstein Observatory X-ray data from a region in Crux (α ≈ 11h45m, δ ≈ 62°) are reported. Morphological as well as rough spectral analysis of a large (≡1°) diffuse feature is performed. The diffuse emission is identified with a SNR, a conclusion supported by comparison with existing radio and optical data. The …