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The Ultraviolet Spectrum of the Magnetic Cataclysmic Variable RX J1802.1+1804
Singh, K. P.; Shrader, C. R.; Barrett, P.
We observed the counterpart to the X-ray source RX J1802.1+1804, an object recently discovered as part of a survey to identify the optical counterparts to ultrasoft X-ray sources in the ROSAT point-source catalog that was subsequently identified as a magnetic cataclysmic variable, with the ultraviolet spectrometers on IUE in low dispersion mode. W…
HIPPARCOS extragalactic link by means of absolute proper motions of stars related to galaxies: Kyiv solution.
Rybka, S. P.; Yatsenko, A. I.; Kharchenko, N. V. +1 more
Absolute proper motions of stars with respect to galaxies obtained within the KSZ and MEGA programmes were used in the determination of spin parameters of the Hipparcos catalogue system relative to the inertial reference frame. The Kyiv part of the Bonn-Potsdam-Kyiv project "Hipparcos extragalactic link by photographic astrometry" is discussed. So…
IUE observations of Beryllium II lines in Lithium-rich giant stars.
de Medeiros, J. R.; Monier, R.; Lebre, A. +1 more
IUE spectra of the Beryllium II region are presented for two Lithium-rich giant stars, HD 9746 and HD 112127. In either spectrum there is no sign of significant Beryllium features at the BeII lines 3130.416Å or 3131.064Å, which seems to indicate that Be was depleted in these two Lithium-rich giants. This suggests that some additional Lithium was p…
Hot Evolved Objects in Different Parent Galaxies: The Stellar Winds of Three Planetary Nebula Nuclei in the Large Magellanic Cloud
Bianchi, Luciana; Vassiliadis, Emanuel; Dopita, Michael
Three planetary nebulae in the Large Magellanic Cloud (LMC) were observed with the Faint Object Spectrograph on board the Hubble Space Telescope. Their central stars display P Cygni-like features in the ultraviolet. We modeled these profiles to derive the stellar wind velocities. The wind velocities of the LMC planetary nebula nuclei (PNNs) are co…
Hubble Space Telescope Spectroscopy of the Carbon Star TX Piscium
Robinson, Richard D.; Johnson, Hollis R.; Querci, Francois +5 more
Ultraviolet spectra obtained with the Hubble Space Telescope of the carbon star TX Piscium (HR 9004) are presented, along with analysis providing information on its outer atmosphere, including flow and turbulent velocities, line formation mechanisms, and variations with time. Both thermal (collisionally excited) and fluorescent emission from the c…
A multiwavelength study of the starburst galaxy NGC7771
Alonso-Herrero, Almudena; Davies, Richard I.; Ward, Martin J.
We present a multiwavelength study of the interacting starburst galaxy NGC7771, including new optical and ultraviolet spectra and a previously unpublished soft X-ray ROSAT image and spectrum. The far-infrared, radio and X-ray fluxes suggest that a massive burst of star formation is currently in progress, but the small equivalent width of the Balme…
Circumstellar PAHs and Carbon Stardust
Tielens, A. G. G. M.
The SWS on ISO has revealed the incredible richness of IR emission features in the spectra of post-AGB objects and planetary nebulae. Besides the well known features at 3.3, 6.2, 7.7, 8.6, and 11.3 µm, a wealth of weaker features is present as well. These studies also reveal detailed variations from source to source, which may be of key impo…
Refined analysis of interplanetary H-Lyα spectra obtained with the Hubble-Space Telescope GHRS spectrometer.
Clarke, J. T.; Scherer, H.; Fahr, H. J.
Here we present a new synoptic analysis of 5 HST-GHRS interplanetary H-Lyα spectra obtained at different lines of sight from different positions of the earth in its orbit. The spectral analysis aimed at the derivation of actual interstellar gas parameters is carried out on the basis of a newly developed Lyα radiation transport code taking into acc…
Multicolor CCD Photometry of the Poorly Studied Globular Cluster NGC 6541
Alcaino, G.; Liller, W.; Alvarado, F. +3 more
We have carried out the first accurate multicolor (UBVRI) CCD photometry for more than 3000 stars (12m.3<V<21m.0) in the field of the globular cluster NGC 6541. This cluster was neglected in photometric studies after two photographic investigations by Alcaino (1971, A&A;, 13, 399; 1979, A&AS, 35, 233). The color…
Spectral Components in the Optical Emission of the Seyfert Galaxy NGC 5548 and the Comparison of Intrinsic Nuclear Spectra with Accreting Corona Model
Czerny, B.; Kuraszkiewicz, J.; Loska, Z.
We study the extensively monitored Seyfert galaxy NGC 5548 and compare its nuclear emission with models of accretion disk with accreting corona. To obtain the intrinsic nuclear spectra from the observed spectra we had to estimate and subtract the contribution from circumnuclear components such as stars, the Balmer continuum and blended FeII lines,…