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Our New View of the Sun - Results from the Solar and Heliospheric Observatory

Harrison, R. A.

Over the last three years the Solar and Heliospheric Observatory (SOHO) has been revolutionising our view of our star, the Sun. A review of some of the new results from SOHO is given here, with a particular emphasis on the solar atmosphere - the source of the so-called `space weather'. The results include a rather unexpected feature of the nature …

SOHO Observations of Density Fluctuations in Coronal Holes

Romoli, M.; Poletto, G.; Noci, G. +5 more

In recent UVCS/SOHO White Light Channel (WLC) observations we found quasi-periodic variations in the polarized brightness (pB) in the polar coronal holes at heliocentric distances of 1.9 to 2.45 solar radii. The motivation for the observation is the 2.5D MHD model of solar wind acceleration by nonlinear waves, that predicts compressive fluctuation…

Galactic kinematics derived from classical cepheids

Zhu, Zi

On the basis of radial velocity and Hipparcos proper motion data, we have analyzed the galactic kinematics of classical Cepheids. Using the 3-D Ogorodnikov-Milne model we have determined the rotational velocity of the Galaxy to be V₀ = 240.5 ± 10.2 km/s, on assuming a glactocentric distance of the Sun of R₀ = 8.5 kpc. The res…

Observations of radio stars at the Valinhos CCD Meridian Circle

Teixeira, R.; Assafin, M.; Lopes, P. A. A. +6 more

We present the astrometric results from the optical observation of 16 stars from the list of \cite[Wendker (1995)]{wend95}, with detected or suspected radio emission. The results are given on the Hipparcos/Tycho reference frame. The stars are evenly distributed in right ascension and the declinations range from -15.6(deg) to +28.6(deg) . This dist…

Classification of the light curves of Miras.

Melikyan, N. D.

On the basis of the analysis of light curves of 223 Mira Ceti type long period variable stars registered by Hipparcos, it is shown, that all these stars by external shape of their light curves can be devided into two groups: stars, showing simple light curves of the sine wave form, and stars with complex light curves, with hump-shaped formations o…

Studies of the cosmic ray radial and latitudinal intensity gradients over the cycle 22 solar minimum period

Kunow, H.; Wibberenz, G.; Heber, B. +7 more

The spatial intensity gradients of galactic and anomalous cosmic ray helium are studied over the 1993.0-1998.0 time period using data from cosmic ray experiments on IMP 8, Ulysses, Voyagers 1 and 2 and Pioneer 10. When combined with the results of previous studies, a remarkable ordering of the radial gradients for the galactic component is found o…

Massive accretion disks in galactic nuclei

Scoville, N. Z.

In the luminous infrared galaxies, very large masses of interstellar matter have been concentrated in the galactic nuclei at radii less than 300 pc as a result of galactic merging, while in lower luminosity systems, this material is probably concentrated by stellar bars and viscous accretion. In both cases, the nuclear region will be highly obscur…

Solar wind isotopic abundance ratios of Ne, Mg, and Si measured by SOHO/CELIAS/MTOF as diagnostic tool for the inner corona

Hilchenbach, M.; Gloeckler, G.; Hovestadt, D. +2 more

SOHO Learns the Cruder Arts of Navigation

Hellemans, A.

SOHO After 30 Months: A Personal View

Gabriel, A. H.