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The Sun as a Star: High Spectral Resolution Solar Data Degraded to Low-Dispersion IUE Resolution
Doyle, J. G.; Cook, J. W.
High spectral resolution (about 0.06 A) solar data for an active region and a large two-ribbon flare degraded to the typical resolution of low-dispersion (about 5 A) spectra of the IUE satellite are presented. This clearly shows the amount of detail yet to be acquired in stellar spectra and indicates the main spectral regions where line blending i…
Faint Object Spectrograph Observations of the Large-Redshift Gravitational Lens Candidate 1208+1011
Maoz, Dan; Schneider, Donald P.; Jannuzi, Buell T. +2 more
We report HST spectroscopic observations of the z = 3.8 gravitational lens candidate 1208+1011. Low-dispersion (R = 200) Faint Object Spectrograph data, covering the wavelength range 3700-7800 A, were obtained for each of the two components (V ~18.3 and 19.8 mag) and for a comparison (blank) field; the fainter component and the blank field are bot…
X-Ray Observations of Planetary Nebulae with Binary Nuclei
Nousek, J. A.; Apparao, K. M. V.; Berthiaume, G. D.
Einstein and EXOSAT satellite observations of X-ray emission from the planetary nebulae A63 and LoTr 5 are reviewed. Both of these systems contain binary central stars. No flux was detected from A63 (central star UU Sge). LoTr 5 (central star IN Com) is a previously unreported X-ray emitter; it showed no statistically significant X-ray variability…
Highly Ionized Gas in the GUM Nebula and Elsewhere: A Comparison of IUE and Copernicus Satellite Results
Savage, Blair D.; Edgar, Richard J.
The data from six high-dispersion IUE echelle spectra are averaged in order to obtain an interstellar absorption line spectrum with an S/N of about 30 and a resolution of about 25 km/s. The interstellar lines of C IV and Si IV are very strong and broad and N V is detected. The profiles for these species and Al III are compared to the Copernicus sa…
EXOSAT Observations of the X-Ray Binary Pulsar 4U 1538-52
Cusumano, G.; Frontera, F.; Orlandini, M. +2 more
Results are reported from a temporal and spectral analysis performed on four EXOSAT observations, part of which were taken from the EXOSAT archive, carried out during March and August 1984. In the first observation an absorbing episode was detected, which may be attributed to an inhomogeneity in the stellar wind of QV Nor; the scale height of this…
Ultraviolet Imaging Telescope Photometry of Massive Stars: The OB Association NGC 206 in M31
O'Connell, Robert W.; Bohlin, Ralph C.; Smith, Andrew M. +6 more
The Ultraviolet Imaging Telescope (UIT) obtained UV images of the giant M31 OB association NGC 206. Magnitudes in bands at 1520 and 2490 A were obtained for 30 massive stars, which demonstrate the effectiveness of UIT for photometry of moderately crowded hot stars to V ~ 21. The UV colors and magnitudes observed for stars in NGC 206 place them in …
X-Ray Observations of the Seyfert 1 Galaxy MCG 2-58-22
Ghosh, K. K.; Soundararajaperumal, S.
Results of the detailed X-ray (0.1-10 keV) spectral analysis of the Seyfert 1 galaxy, MCG 2-58-22, are presented based on the EXOSAT observations on 1984 November 16-26. X-ray spectra of this source were obtained from the EXOSAT archives. Weak, soft flux (0.1-2 keV) variations were found on time scales of 2-3 days, and no variations of the hard fl…
AL II Emission-Line Strengths in Low-Density Astrophysical Plasmas
Feibelman, W. A.; Keenan, F. P.; Harra, L. K. +1 more
Theoretical values of the emission-line ratio R are derived for the transitions 3s2 1S-3s3p 3P2 and 3s2 1S-3s3p 3P1 in Al II, at 2660 and 2669 A, respectively. These ratios are compared with IUE observations of the planetary nebula NGC 7027 and the symbiotic star RR Tel, to illustrate the usefulness of the R as an electron density diagnostics. A v…
EXOSAT Observations of the Broad-Line Radio Galaxy 3C 382
Ghosh, K. K.; Soundararajaperumal, S.
X-ray observations of the broad-line radio galaxy 3C 382 were carried out with EXOSAT on many occasions (>20) between 1983 and 1985. Low and Medium Energy (LE and ME) spectra of this source were obtained from the EXOSAT data base. The hard-X-ray luminosity light curve of 3C 382 which was constituted from Ariel V, HEAO 1, Einstein, EXOSAT, and G…
Absorption-Line Profiles in a Companion Spectrum of a Mass-losing Cool Supergiant
Boehm-Vitense, Erika; Rodrigues, Liliya L.
Cool star winds can best be observed in resonance absorption lines seen in the spectrum of a hot companion, due to the wind passing in front of the blue star. We calculated absorption line profiles that would be seen in the ultraviolet part of the blue companion spectrum. Line profiles are derived for different radial dependences of the cool star …