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Detection of Accreting Gas toward HD 45677: A Newly Recognized, Herbig Be Proto--Planetary System
Grady, C. A.; Perez, M. R.; The, P. S. +4 more
We report the detection of high-velocity, accreting gas toward the BE(e) star with IR excess and bipolar nebula, HD 45677. High-velocity (+200 to +400 km/s), variable column density gas is visible in all IUE spectra from 1979 to 1992 in transitions of Si II, C II, Al III, Fe III, Si IV, and C IV. Low-velocity absorption profiles from low oscillato…
Imaging of the Gravitational Lens System PG 1115+080 With the Hubble Space Telescope
Holtzman, J. A.; Ewald, S. P.; Schneider, D. P. +14 more
This paper is the first of a series presenting observations of gravitational lenses and lens candidates, taken with the Wide Field/Planetary Camera (WFPC) of the Hubble Space Telescope (HST). We have resolved the gravitational lens system PG 1115+080 into four point sources and a red, extended object that is presumably the lens galaxy; we present …
The Hubble Space Telescope Snapshot Survey. III. Further Observations in Search of Gravitationally Lensed Quasars
Maoz, D.; Lahav, O.; Schneider, D. P. +4 more
We present new HST Snapshot Survey observations of 163 high-luminosity z > 1 quasars, bringing the total number observed to date in the survey to 347 quasars. Each exposure was searched for evidence of gravitational lensing. Among the newly observed quasars, six have additional point sources at separations of 2"-6", but in all six cases ground-…
The Circumstellar Gas Surrounding 51 Ophiuchi: A Candidate Proto--Planetary System Similar to beta Pictoris
Grady, C. A.; Silvis, J. M. S.
Combined archival and recent International Ultraviolet Explorer (IUE) observations of the star, 51 Oph, reveal the presence of variable, accreting gas with velocities as large as + 100 km/s relative to the system. The electron number density of the circumstellar gas is comparable to that observed around the candidate proto-planetary system, Beta P…
RE 1016-053: A Pre-Cataclysmic Binary, and the First Extreme Ultraviolet and X-Ray Detections of DAO White Dwarf
Barstow, M. A.; Bergeron, P.; Holberg, J. B. +4 more
Photometric observations and analysis of the optical, UV, EUV, and X-ray spectra are presented for the EUV/X-ray source RE 1016-53. Multiwavelength observations of RE 1016-53 point out that it is a precataclysmic binary. Optical spectra exhibit the steep blue continuum and Balmer absorption typical of a hot white dwarf, but there are bright, narro…
The Structure of the Core of 47 Tucanae from Hubble Space Telescope Observations
Ferraro, Francesco R.; Paresce, Francesco; de Marchi, Guido
A set of moderately deep, high-resolution images of the core of the Galactic globular cluster NGC 104 (47 Tucanae) taken by the Faint Object Camera F/48 relay on the Hubble Space Telescope through the filters F140W, F220W, and F342W are presented and analyzed. The core is completely resolved in these bands for the first time, with approximately 35…
Ultraviolet Polarimetry and Spectroscopy of the BL Lacertae Object PKS 2155-304
Anderson, Scott F.; Miller, Bryan W.; Smith, Paul S. +3 more
We present ultraviolet spectropolarimetry of the BL Lac object 2155 - 304. These observations were made using the Hubble Space Telescope and the Faint Object Spectrograph and, represent the first opportunity to study the wavelength dependence of the UV (1360-3300 A) linear polarization in a BL Lac object. Nearly simultaneous ground-based optical p…
Proof for a wind from the hot component in the symbiotic system EG Andromedae.
Vogel, M.
One of the most debated issue in symbiotic research concerns the nature of the hot component. In this Letter we give observational evidence that in the symbiotic binary EG And the hot compact star loses mass through a stellar wind. The wind velocity is ≈ 500 km s -1, and the mass loss rate is Mṡ ≈ 5 × 10-9 Msu…
Chromospherically active Stars. XI. Giants With Compact Hot Companions and the Barium Star Scenario
Henry, Gregory W.; Fekel, Francis C.; Busby, Michael R. +1 more
We have determined spectroscopic orbits for three chromsopherically active giants that have hot compact companions. They are HD 160538 (KO III + wd, P = 904 days), HD 165141 (G8 III + wd, P approximately 5200 days), and HD 185510 (KO III + sdB, P = 20.6619 days). By fitting an IUE spectrum with theoretical models, we find the white dwarf companion…
The Luminosity Dependence of the X-Ray Spectrum of the Transient 42 Second Pulsar EXO 2030+375
Parmar, A. N.; White, N. E.; Reynolds, A. P.
We report on the evolution in the X-ray spectrum of the transient X-ray pulsar EXO 2030 + 375 during part of an outburst in 1985 May-August. The overall continuum spectral shape is similar to that of other accreting pulsars and can be represented by a power-law spectrum modified at low energies by significant absorption and at high energies either…