Search Publications
Wide Field Camera Observations of Baade's Window
Faber, S. M.; Holtzman, Jon A.; O'Neil, Earl J., Jr. +7 more
We have observed a field in Baade's Window using the Wide Field Camera (WFC) of the Hubble Space Telescope (HST) and obtain V- and I-band photometry down to V approximately 22.5. These data go several magnitudes fainter than previously obtained from the ground. The location of the break in the luminosity function suggests that there are a signific…
Quasiperiodic Jovian Radio bursts: observations from the Ulysses Radio and Plasma Wave Experiment
MacDowall, R. J.; Kaiser, M. L.; Desch, M. D. +3 more
The Ulysses flyby of Jupiter has permitted the detection of a variety of quasiperiodic magnetospheric phenomena. In this paper, Unified Radio and Plasma Wave Experiment (URAP) observations of quasiperiodic radio bursts are presented. There appear to be two preferred periods of short-term variability in the Jovian magnetosphere, as indicated by two…
Deceleration of Interstellar Hydrogen at the Heliospheric Interface
Bertaux, Jean-Loup; Clarke, John T.; Lallement, Rosine
High-resolution spectra of nearby stars show absorption lines due to material in the local interstellar cloud. This cloud is deduced to be moving at 26 kilometers per second with respect to the sun, and in the same direction as the "interstellar wind" flowing through the solar system. Measurements by the Ulysses spacecraft show that neutral helium…
The Hot Stellar Component in Elliptical Galaxies and Spiral Bulges. I. The Far-Ultraviolet Spectrum of the Bulge of M31
Ferguson, Henry C.; Davidsen, Arthur F.
We present a spectrum of the bulge of M31 from 1850 A to the Lyman limit measured through a 9" X 116" aperture by the Hopkins Ultraviolet Telescope (HUT) during the Astro-1 space shuttle mission in 1990 December. Apart from airglow, no significant emission features are present in the spectrum. A search for stellar absorption features reveals sever…
The Early Ultraviolet Spectral Evolution of Nova Cygni 1992
Ake, T. B.; Shore, Steven N.; Sonneborn, George +2 more
We report on the high resolution ultraviolet line profile evolution of Nova Cygni 1992 using the International Ultraviolet Explorer (IUE) satellite and the Goddard High Resolution Spectrograph (GHRS) on the Hubble Space Telescope (HST). Our observations cover the period from discovery in 1992 February through 1993 April. The initial expansion velo…
Synthetic UV Lines of Si IV, C IV, and He II from a Population of Massive Stars in Starburst Galaxies
Robert, Carmelle; Heckman, Timothy M.; Leitherer, Claus
We present the first results of our study of the massive star population in starburst galaxies based on UV data. We have synthesized the Si IV 1400, C IV 1550 and He II 1640 lines for both a continuous and an instantaneous burst of star formation with approximately solar chemical composition. Our code uses the latest generation of stellar evolutio…
A model for the 89 Herculis system.
Waters, L. B. F. M.; Mayor, M.; Trams, N. R. +1 more
We report new radial velocity measurements of the F2 supergiant 89 Her that confirm the binary nature of this star. A period search yields an orbital period of 288.4 +/- 0.7 days, in close agreement with earlier results. We also present intermediate resolution spectra in the wavelength range 3500 - 11,000 A, with numerous emission lines. We use th…
Counterstreaming suprathermal electron events upstream of corotating shocks in the solar wind beyond ∼2 Au: Ulysses
McComas, D. J.; Goldstein, B. E.; Bame, S. J. +3 more
Enhanced fluxes of suprathermal electrons are commonly observed upstream of corotating forward and reverse shocks in the solar wind at heliocentric distances beyond ∼2 AU by the Los Alamos plasma experiment on Ulysses. The average duration of these events, which are most intense immediately upstream from the shocks and which fade with increasing d…
Detection of Boron, Cobalt, and Other Weak Interstellar Lines toward zeta Ophiuchi
Lambert, D. L.; Federman, S. R.; Gilliland, R. L. +1 more
Numerous weak lines from interstellar atomic species toward Zeta Ophiuchi were observed with the Goddard High-Resolution Spectrograph. Of particular note are the first interstellar detection of cobalt and the detection of boron in this sight line. These measurements provide estimates for the amount of depletion for the two elements. Boron, a volat…
On the relative C,N,O abundances and the evolutionary status of yellow symbiotic stars.
Nussbaumer, H.; Schmid, H. M.
Symbiotic binaries consist of a cool giant and a hot radiation source, which is ionizing the nebula associated with the system. Yellow symbiotic stars can be divided according to their IR colors into s-type (stellar) and d'-type (dust) systems. The s-types are relatively narrow systems, with orbital periods of several hundred days. They contain hi…