Search Publications

Measurements of the sky background using the HST Faint Object Camera.

Hook, R. N.; Fosbury, R. A. E.; Caulet, A.

The results of a novel method of measuring the three dominant components of the sky brightness from the Hubble Space Telescope orbit are reported. The shadows cast by an occulting finger in the Faint Object Camera (FOC), when the field is dispersed with an objective prism, are separated into three features: the geocoronal Lyα and neutral oxygen ai…

The Case of the Blue Stragglers

Bailyn, Charles

Ulysses charged particle measurements between 1 and 5 AU from the sun

Smith, E. J.; Wenzel, K. -P.; Page, D. E.

Proton fluxes obtained by two instruments carried on the ESA/NASA Ulysses spacecraft are reported for the period from launch in October 1990 till Jupiter encounter in February 1992. Proton energy ranges are 24-59, 71-99, 130-320, 320-2100 and > 2100 MeV. The Sun was very active during this period, the events of March 1991 being some of the larg…

The identification of the new gamma-ray pulsar PSR 1055-52 from COS-B data.

Song, L. -M.; Lu, T.

A constraint-logic based implementation of the coarse-grained approach to data acquisition scheduling of the International Ultraviolet Explorer orbiting observatory

McCollum, Bruce; Graves, Mark

The International Ultraviolet Explorer (IUE) satellite observatory has been in operation continuously since 1978. It typically carries out several thousand observations per year for over a hundred different science projects. These observations, which can occur in one of four different data-taking modes, fall under several satellite-related constra…

Pulsed Gamma Rays from Geminga

Cheng, K. S.; Ma, Y. Q.

The pulsed gamma ray spectrum is obtained by analyzing COS-B data of observation no. 14, 39, 54 and 64. We find that the pulsed spectrum differs significantly from that of previous reports in which the pulsed component and steady component are not separated. A clear spectral break of the pulsed spectrum occurs at ~ 100 MeV and the majority of the …

Recent Magnetic Field Results from the Galileo and Ulysses Spacecraft: Discussion

Wallis, M. K.; Southwood, D. J.; Miller, S.

The HIPPARCOS astrometric satellite and visual double stars

Pannunzio, Renato

Astrometry from the Earth, in the past as well as at present, is described with particular attention to the evolution of the observational techniques from the last century to date and to the consequent improvement of results obtained by continually improved techniques. The scientific goals of the Hipparcos mission, the first astrometric space miss…

U Energy Distribution of AZ Cassiopeiae

Kang, Young-Woon

The IUE low dispersion spectra of AZ Cas have been analyzed for line identifications and energy distribution in ultraviolet region. Highly ionized atoms, Si IV and C IV are identified. We could infer a temperature range of the B star between 15,000K and 20,000K. The energy density distribution shows a hump between IUE short wavelength and long wav…

Column Densities of Interstellar Gas in the Direction of the Star \Epsilon ORI (B0 IA)

Mentese, H. H.

We have investigated the star ɛ Ori with IUE high resolution SWP spectrum in order to derive curve of growth and column densities of Al II, Si II, S II, Fe II, Ni II and Zn II. It has been possible to fit these ions on one empirical curve of growth with a velocity parameterb = 11 km s^‑1 for the star studied.