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First Results from the Goddard High-Resolution Spectrograph: C i, S i, and CO toward XI Persei and the Physical Conditions in Diffuse Clouds
Ebbets, Dennis C.; Savage, Blair D.; Lambert, David L. +5 more
Observations made by the Goddard High Resolution Spectrograph of the cool, neutral interstellar gas in the line of sight to Xi Per are reported. Heliocentric velocities and equivalent widths were measured for absorption lines of C I and S I. Synthetic spectra were computed and fitted to the observed CO(2-0) and (3-0) bands in the A IPi - X 1Sigma(…
Far-Ultraviolet Spectroscopy of the Quasar UM 675 with the Faint Object Spectrograph on the Hubble Space Telescope
Cohen, Ross D.; Burbidge, E. M.; Rosenblatt, E. I. +6 more
Observations of UM 675 with the HST and FOS demonstrate the proper functioning of the FOS. We detect light in UM 675 down to 520 A in the rest frame and set limits to He I emission, the He I Gunn-Peterson effect at z = 2.148, and Lyα absorption at z~0.5.
Stellar Photometry with the Hubble Space Telescope Wide-Field/Planetary Camera: A Progress Report
Schneider, Donald P.; Lauer, Tod R.; Faber, S. M. +16 more
We describe the prospects for the use of the Wide-Field/Planetary Camera (WFPC) for stellar photometry. The large halos of the point- spread function (PSF) resulting from spherical aberration and from spatial, temporal, and color variations of the PSF are the main limitations to accurate photometry. Degradations caused by crowding are exacerbated …
IUE Observations of NGC 1068: The Extremely Luminous Starburst Knots
Bruhweiler, F. C.; Truong, K. Q.; Altner, B.
We present a complete study of the UV characteristics of the starburst knots in the inner 3 kpc region of NGC 1068 mapped by the International Ultraviolet Explorer (IUE) satellite. These knots likely represent the most luminous H II regions yet studied at optical and ultraviolet wavelengths. Comparisons indicate the brightest UV knot, knot 1, is 3…
Observations of the Peculiar Object MWC 560 in Outburst
Dapergolas, A.; Michalitsianos, A. G.; Kontizas, M. +4 more
The results of ultraviolet spectroscopy, photoelectric photometry, and supplemental high-resolution H(alpha) spectroscopy of a photometric outburst of MWC 560 are discussed. Ultraviolet spectra are shown to be consistent with the ejection of an optically thick shell that produced strong absorption blends of Fe II and Cr II. The velocities reported…
X-Ray Emission from Hybrid-Chromosphere Stars
Brown, Alexander; Drake, Stephen A.; Linsky, Jeffrey L. +1 more
The observations of hybrid stars made by the Exosat X-ray satellite are considered, and emphasis is placed on the hybrid star alpha TrA. Attention is focused on the determination of the column density of IS hydrogen toward the stars in order to interpret X-ray observations of stellar coronal emission. The coronal properties of alpha TrA are discus…
The Many Faces of F Stars: A Rotational Modulation Study of Capella, Procyon, and Caph with the International Ultraviolet Explorer
Ayres, Thomas R.
Far-UV spectroscopy of the F stars Capella, Procyon, and Caph is reported. Although all three stars are regard as chromospherically 'active', none exhibited any sensible rotational modulations, indicating a smooth surface distribution of chromospheric emission. Balancing this nonsolar behavior are a variety of puzzling differences among the three …
Ultraviolet and Optical Spectroscopy of the R Aquarii Symmetrical Jet
Hollis, J. M.; Kafatos, M.; Michalitsianos, A. G. +2 more
The first ultraviolet spectrum of the southwest (SW) component of the symmetrical jet in the R Aquarii binary system has been obtained in the range 1200-2000 A with the IUE. These results are compared to more encompassing spectra of the central H II region taken at the same time and also similar spectra of the northeast (NE) jet component obtained…
Mass Outflow in the Nearby Proto--Planetary System beta Pictoris
Grady, C. A.; Kondo, Yoji; Bruhweiler, Frederick C.
Previous spectral studies of circumstallar dust around the nearby, candidate proto-planetary system, Beta Pictoris, has detected only infalling gas. The lack of detectable mass outflow has been critical in the interpretation of the origin of the circumstellar gas and in our understanding of the evolutionary status of the Beta Pictoris system. IUE …
Rotational Modulation in IUE Spectra of Cool Dwarf Chromospheres. I. Data Analysis and Period Search Techniques
Hallam, K. L.; Altner, B.; Endal, A. S.
Time-sequenced IUE spectra of a number of a bright F-K dwarfs have been used to investigate rotational modulation in several important chromospheric and transition emission lines. Stellingwerf's phase dispersion minimization (PDM) technique forms the basis of this time-series analysis of these sparsely sampled, irregularly spaced observational seq…