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An IUE Search for Star Formation in Ellipticals with Gaseous Disks
Renzini, Alvio; Burstein, David; Bertola, Francesco +1 more
New IUE observations are presented of NGC 5077, an elliptical galaxy known to have a Hα bright gaseous disk in its central region. The ultraviolet spectral energy distribution of NGC 5077 is compared to those of the bulges of two galaxies, M31 and NGC 3115, that are of similar Mg_2_ absorption-line strength and are known not to contain obvious gas…
Ultraviolet spectroscopy of nova MUSCAE 1991.
Panagia, N.; Horne, K.; Shrader, C. R. +4 more
We report on a series of ultraviolet spectroscopic observations made with the IUE satellite, which sampled critical outburst stages of the soft X-ray transient Nova Muscae 1991. Continuum light curves, and a multi-epoch line analysis are presented. In addition, a single epoch optical-UV spectra obtained with the HST/FOS is discussed. The optical-U…
The Companion of the 18d Classical Cepheid YZ CAR
Evans, Nancy R.; Butler, John
We have obtained a deep IUE spectrum of the 18d Cepheid YZ Car. Flux has been detected at the level of 1-2 X 10^-15 ergs cm^-2 A^-1 sec^-1 from 1200 to 200 A, which we identify as the companion in the binary system. Since this is at least partly a result of "camera artifacts" built up during a long exposure, this is an upper limit to the flux of t…
Deflection of Light by the Earth
Gould, Andrew
General relativity predicts that light rays are deflected by gravitational fields. This effect has been observed with various degrees of precision on distance scales from 10 exp 11 to 10 exp 23 cm and on mass scales from 10 exp -3 to 10 exp 13 solar masses. The Hipparcos satellite can detect deflection of light by the earth, and can thereby extend…
Periodicities of Jovian broad-band kilometric radiation observed by Ulysses
Rabl, G. K. F.
Observations of the Unified Radio and Plasma Wave (URAP) instrument onboard the Ulysses spacecraft have been used to analyze periods inherent in the Jovian broad-banded kilometric radio emission (bKOM) between 29 and 47 kHz. It is demonstrated, by using power spectrum analysis and linear prediction time filtering that the long-term fluctuations of…
Focus History of the Hubble Space Telescope - Launch to May 1993
Burrows, C. J.; Hasan, H.; Schroeder, D. J.
Since the launch of the Hubble Space Telescope (HST) the secondary mirror of the telescope has been moved several times in order to collimate the telescope and also to define a position of best focus. In addition to these moves the focus position changes over time because of water desorption by the graphite epoxy in the metering truss. We report h…
Resolved Structure in M33 Supernova Remnants
Blair, William P.; Davidsen, Arthur F.
We present WF/PC narrow band [S II] lambda-6725 images of two M33 supernova remnants obtained with the Wide Field/Planetary Camera on the Hubble Space Telescope. Comparison of these images with ground-based CCD data indicates that HST has resolved the nebular structures into shells or partial shells, permitting improved measurements of the diamete…
Temperatures of Zodiacal dust
Divine, Neil; Grün, Eberhard; Staubach, Peter
Temperatures of interplanetary dust particles have been determined by calculating the termal emission from dust concentrations according to the "Five Populations of Interplanetary Meteroids" model by Divine ( J. geophys. Res., in press, 1993) and matching it with the observed zodiacal thermal emission. Properties of the meteoroid populations are d…
Internal Ultraviolet Explorer Observations of the white Dwarf Nucleus of the Very Old, Diffuse Planetary Nebula, IW-2
Bruhweiler, F. C.; Feibelman, Walter A.
UV low-dispersion spectra of the central star of the faint planetary nebula, IW-2, were obtained with the IUE. The apparent large diameter of the very diffuse nebula, about half that of the moon, as seen on the Palomar Sky Survey plates by Ishida and Weinberger (1987), indicates this object to be potentially quite evolved, and nearby. The IUE spec…
The radial velocity and binarity of HD 153919 (4U 177A T The radial velocity and binarity of HD 153919 (4U 1700-37).
Stickland, D. J.; Lloyd, C.
New measurements of radial velocities from high-resolution lUE spectra of the massive X-ray binary HD 153919 give a velocity amplitude that is markedly smaller than that found in earlier studies, namely 5 km s-1, compared with previous values of around 20 km s-1. If such measurements relate to orbital motion, then the inferre…