Search Publications
Binary Star Observations with the Hubble Space Telescope Fine Guidance Sensors. I. ADS 11300
Benedict, G. F.; Franz, O. G.; Kreidl, T. J. N. +13 more
According to an orbit based on measures mostly near apastron, the binary ADS 11300 = Hu 581 = WDS 18229 + 1458 passed through periastron in 1984 at an angular separation below 0.1 arcsec. On the assumption that one accurate measurement near periastron may serve to define its orbit, ADS 11300 was selected for Early Release Observation (ERO) with th…
Densities and Abundances of Hot Cometary Ions in the Coma of P/Halley
Balsiger, H.; Ip, W. -H.; Goldstein, B. E. +3 more
The densities of the hot component in the ion population observed in the P/Halley coma by the ion mass spectrometer aboard the Giotto spacecraft has been recomputed, and the results are reported. Except for protons and H2(+), all densities are found to be at least an order of magnitude higher than predicted by the physicochemical model of Schmidt …
The Binary Feige 24: The Mass, Radius, and Gravitational Redshift of the DA White Dwarf
Thorstensen, John R.; Vennes, Stephane; Shipman, Harry L. +1 more
Observations are reported which refine the binary ephemeris of the Feige 24 system, which contains a peculiar hot DA white dwarf and an M dwarf with an atmosphere illuminated by extreme ultraviolet radiation from the white dwarf. With the new ephemeris and a set of IUE high-dispersion spectra, showing phase-dependent redshifted C IV, N V, and Si I…
The UV properties of normal galaxies. I. The IUE data.
Longo, G.; Capaccioli, M.; Ceriello, A.
As a first step toward a better understanding of the energy distribution of normal galaxies at wavelengths shorter than 3300 A, all IUE low resolution spectra of normal galaxies have been reduced to a photometric system consisting of seven intermediate-widths bands, five of which matching the ANS photometric system. Dereddened ultraviolet magnitud…
Stellar wind properties of A-type hypergiants.
Stahl, O.; Wolf, B.; Smolinski, J. +1 more
The visually bright objects from the Magellanic Clouds are examined in terms of observed properties that indicate properties relevant to the stellar wind. IUE observations are accomplished in the long-wavelength primary echelle mode in the optical wavelength near H-alpha of the objects HD 33579 and HD 7583. The Fe-II lines are found to have widths…
Comet P/Halley's dust production rate at Giotto encounter derived from Halley Multicolour Camera observations
Keller, H. U.; Thomas, N.
Optical constants for the dust from Comet P/Halley have been determined from Halley Multicolour Camera observations by applying the dust size distribution and the total mass impacting the Giotto spacecraft. The quantity of dust is found to be 0.080 rho exp 2/3 where rho is the dust particle bulk density in g/cu cm at an effective wavelength of 653…
An Interactive Companion to the S Star HD 35155
Johnson, Hollis R.; Ake, Thomas B., III; Ameen, Mudhaffer M.
Low-dispersion UV spectra taken by the IUE satellite of an S star HD 35155 are presented. It is shown that the spectra contain strong emission lines of multiply ionizes species and an excess continuous emission shortward of 2000 A. Because neither the photospheres nor chromospheres of S stars are expected to produce multiply ionized ions, the emis…
Probing the Galactic Halo along the 3C 273 Sight Line Using IUE
York, Donald G.; Blades, J. C.; Bohlin, Ralph C. +2 more
High-resolution spectra of the QSO 3C 273 were obtained in 1989 and added to two spectra recorded in 1982. The co-added spectra represent 600,000 s of integration at a resolution of 30 km s^-1^ from 1200 to 2000 A. The line of sight passes through the Virgo Cluster the entire halo of the Milky Way, at Galactic latitude b = 64^deg^, and foreground …
IUE observations of the bright Herbig AE star HD 104237.
Talavera, A.; Catala, C.; The, P. S. +4 more
IUE observations are noted to indicate that HD 104237 exhibits the same UV, visible, and IR spectral properties as the Herbig Ae stars AB Aur and HR 5999. It is accordingly concluded that HD 104237 is a 2.1 solar-mass Herbig AE star. With respect to HR 5999, the chromospheric and transition region emission-line flux of HD 104237 is sufficiently la…
Scattering of X-rays on the winds of supergiant X-ray binaries.
Haberl, F.
Monte-Carlo simulations of Thomson scattering of X-rays in the stellar wind of OB stars in supergiant X-ray binaries show that at least part of the low-energy excess seen in the X-ray spectra during phases of high absorption can be explained by scattering of X-rays around a dense region in the wind obscuring the direct radiation. In the case of 4U…