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Faint Object Camera Observations of the Shape and Expansion of SN 1987A
Panagia, N.; Jakobsen, P.; Macchetto, F.
New visible and near-UV imagery of SN 1987A obtained 1754 days after outburst with the Faint Object Camera on-board the Hubble Space Telescope is presented. A comparison between these data and previous FOC observations obtained 1278 days after outburst reveal that the supernova dimmed by a factor 0.35 +/- 0.04 between the two observations, corresp…
First Ultraviolet Spectropolarimetry of Radio-selected BL Lacertae Objects
Smith, Paul S.; Allen, Richard G.; Angel, J. R. P.
We present ultraviolet spectropolarimetry of the BL Lac objects OJ 287 and 0754+100 (OI 090.4) acquired with the Faint Object Spectrograph of the Hubble Space Telescope. These are the first such observations of radio-selected BL Lac objects and the polarimetry spans the wavelength range 1580-3300 A in the observer's frame. Neither object exhibited…
A Spectroscopic Search for Colliding Stellar Winds in O-Type Close Binary Systems. IV. IOTA Orionis
Wiggs, Michael S.; Gies, Douglas R.; Bagnuolo, William G., Jr.
We present H-alpha and He I 6678 A line profiles for the eccentric orbit binary Iota Ori. We have applied a tomography algorithm which uses the established orbital velocity curves and intensity ratio to reconstruct the spectral line profiles for each star. The He I profiles appear as pure photospheric lines, and H-alpha shows variable emission in …
Observations of Nearby Interstellar Gas and Dust in the Direction toward the Globular Cluster omega Centauri
Bates, B.; Wood, K. D.
High-resolution spectra of Na I D interstellar lines are presented for six stars which lie within 4°.0 of the globular cluster ω Centauri and at distances in the approximate range 100-600 pc. For one star (HD 116226) we discuss also the Ca II K line profile and spectra obtained with lUE. Sky flux images of the ω Cen field show considerable structu…
Faint Object Camera Far-Ultraviolet Objective Prism Observations of 12 Z > 3 Quasars
Boksenberg, A.; Barbieri, C.; Weigelt, G. +16 more
We present the first results of an exploratory objective prism survey of the far-ultraviolet (λλ1200-1800) spectra of high-redshift quasars obtained with the Faint Object Camera on-board the Hubble Space Telescope. The prime objective of this survey is to identify one or more candidates among the known quasars at Ζem > 3 with suffici…
Ultraviolet Properties of Individual Hot Stars in Globular Cluster Cores. I. NGC 1904 (M79)
Altner, B.; Matilsky, T. A.
As part of an observing program using the IUE satellite to investigate the properties of stars within the cores of Galactic globular clusters, we have obtained three spectra of the cluster NGC 1904 (M79). All three were long-integration-time, short-wavelength (SWP) spectra obtained at the so-called 'center-of-light', and all three showed evidence …
A Spectral Study of Four X-Ray--selected BL Lacertae Objects with EXOSAT
Maraschi, L.; Tagliaferri, G.; Treves, A. +2 more
We present new EXOSAT spectral results for four X-ray-selected BL Lac objects (H0323+022, H0414+009, H1426+428, and H1722+ 119). The data were retrieved from the EXOSAT data base. A spectral analysis was performed on the overall low-energy plus medium-energy distributions, which were modeled with a single, absorbed power law. In one case (H1426+42…
A Determination of the Basic Atmospheric Parameters of phi Cassiopeiae
Rosenzweig, Patricia; Anderson, Lawrence
By constructing non-LTE spherical model atmospheres, we have calculated a theoretical distribution of the emergent radiation that best matches the observed distribution of the supergiant Phi Cas, and so derived its effective temperature, surface gravity, and radius. Since Phi Cas is very likely a member of the open cluster NGC 457, we made extinct…
Ultraviolet and Optical Studies of Binaries with Luminous Cool Primaries and Hot Companions. IV. Further IUE Detections
Parsons, Sidney B.; Ake, Thomas B.
We have obtained IUE spectra for 31 middle and late-type giant and supergiant stars whose TD-1 fluxes or ground-based spectra indicate the presence of a hot component, or whose radial velocities indicate an unseen component. Stellar components earlier than type F1 were detected in 22 cases. While 20 of the hot secondaries are seen weakly in optica…
Detection of Far-Ultraviolet High-Excitation Line Emission and Lyman- beta Absorption in the Gravitational Lens Q0957+561
Kondo, Y.; Bruhweiler, F. C.; Michalitsianos, A. G. +7 more
Test runs with a new data processing software system on archival spectra obtained by the International Ultraviolet Explorer (IUE) reveal high-excitation emission lines in the gravitationally lensed binary quasar 0957+561. The lines of O VI λλ1031,1037 and S VI λ2933,945 are readily seen in a single 390 minute, low-dispersion IUE exposure, when cal…