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Ulysses-UVCS Coordinated Observations

Romoli, M.; Poletto, G.; Kohl, J. +5 more

We present results from SOHO/UVCS measurements of the density and flow speed of plasma at the Sun and again of the same plasma by Ulysses/SWOOPS in the solar wind. UVCS made measurements at 3.5 and 4.5 solar radii and Ulysses was at 5.1 AU. Data were taken for nearly 2 weeks in May June 1997 at 9 10 degrees north of the equator in the streamer bel…

Formation of resonance spectral line profiles in stellar wind: Theory and observations

Sapar, L.; Sapar, A.

The theory of the formation of resonance spectral line profiles in the stellar wind of hot stars has been elaborated taking into account the presence of microturbulent motions. In this case the local frequency redistribution in the line profile function is incomplete. This circumstance generates dominating backscattering of photons and drastic cha…

The proper-motion signal of unresolved binaries in the Hipparcos catalogue

Brosche, P.; Odenkirchen, M.

We present an investigation of the differences between quasi-instantaneous stellar proper motions from the Hipparcos catalogue and long-term proper motions determined by combining Hipparcos and the Astrographic Catalogue. Our study is based on a sample of about 12000 stars of visual magnitude from 7 to 10 in two declination zones on the northern a…

The Highest Solar Wind Velocity in a Polar Region Estimated from IPS Tomography Analysis

Tokumaru, M.; Kojima, M.; Fujiki, K. +3 more

Observation of a ~ 7 MeV Electron Super-flux at 5 AU by Ulysses

Kunow, H.; Muller-Mellin, R.; Bothmer, V. +4 more

From the Ulysses launch up to the end of 1995, the 4-10 MeV energy electron count rate of the COSPIN/KET instrument has been consistent with simple expectations from Jovian electrons propagation. From the beginning of 1996 to the end of 1998, Ulysses was below ~ 30 degrees of heliographic latitude and between 4.5 and 5.4 AUs from the Sun, making i…

Ground-based and HST optical-infrared studies of quasar host galaxies at low redshift

McLure, R. J.; Dunlop, J. S.; Hughes, D. H. +3 more

We describe the results from a series of ground-based and HST programs aimed at investigating the host galaxies of both radio-loud and radio-quiet quasars (RLQs & RQQs) and FRII radio galaxies (RGs) at low redshifts (0.1 < z < 0.3). Our results are in good agreement with those of other recent studies of host galaxies. In general the host…

Classification of the light curves of Mira variables

Melikian, N. D.

Based on an analysis of light curves of 223 long-period variables of the Mira Ceti type, recorded using the HIPPARCOS space telescope, it is shown that all the light curves of these stars can be divided by outward form into two groups: stars exhibiting simple light curves of sinusoidal shape and stars with complicated light curves, with hump-shape…

BOK Globules in the Large Magellanic Cloud

Walsh, J. R.; Chu, Y. -H.; Garnett, D. R. +1 more

We report the discovery of small, isolated dust clouds in the Large Magellanic Cloud (LMC) that are excellent candidates for counterparts to the Bok globules observed in the Galaxy. We detect these small clouds silhouetted against diffuse Hα emission on the basis of parallel imaging with the Wide Field Planetary Camera 2 on the Hubble Space Telesc…

EUV and Radio Observations of an Equatorial Coronal Hole

Kerdraon, A.; Fludra, A.; Landi, E. +1 more

An equatorial coronal hole has been observed on 18 and 19 October 1996 with SOHO-CDS and with the Nancąy Radioheliograph (RH). The CDS EUV line intensities are used to determine the coronal hole Differential Emission Measure (DEM); in turn this is used to compute the radio brightness temperature T_b at the observed frequencies, leaving t…

O-Mode Emission at the Io Torus: A Real or Virtual Source?

MacDowall, R. J.; Farrell, W. M.; Hess, R. A.

We examine the nature of an ordinary (o-mode) emission observed near the Io plasma torus during the 1992 Ulysses encounter with Jupiter. The emission appears to intensify by factors of 10-100 in local torus density depletions. We examine whether these intensifications are due to local generation within the density depletion or reflection of a remo…