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Latitudinal and radial variation of >2 GeV/n protons and alpha particles in the southern heliosphere at solar maximum: Ulysses cospinket and neutron monitor network observations
Kunow, H.; Wibberenz, G.; Heber, B. +7 more
Ulysses, launched in October 1990, began in its second out-of-ecliptic orbit in September 1997 and its second fast latitude scan in November 2000. In contrast to the first orbit with the Sun declining to low activity, we are now at solar maximum conditions. The Kiel Electron Telescope (KET) on-board Ulysses measures proton and alpha-particles in t…
XMM-Newton observations of the BL Lac MS 0737+7441
Boller, Th.; Brinkmann, W.; Keil, R. +5 more
We report on the XMM-Newton observations of the BL Lac object MS 0737.9+7441 during the performance verification phase. A simple power-law fit provides an adequate description of the integrated spectrum in the 0.2-10 keV energy band. The photon index is slightly steeper in the EPIC pn data with Gamma = (2.38 +/- 0.01) compared to the EPIC MOS data…
A Survey of Field-Aligned Mach Number and Plasma Beta in the Solar Wind
De Keyser, Johan; Poedts, Stefaan; Roth, Michel +1 more
We have surveyed solar wind plasma beta and field-aligned Alfvénic Mach number using Ulysses and Wind data. We show the characteristic timescale and occurrence frequency of `magnetically dominated' solar wind, whose interaction with a planetary magnetosphere may produce a bow shock with multiple shock fronts. We discuss radial, latitudinal, and so…
Associating the Solar Wind Measured by Ulysses with its Source at the sun
Habbal, Shadia Rifai; Woo, Richard
Radio occultation, ultraviolet, and white-light measurements have expanded our knowledge of the morphology of density and velocity in polar coronal holes, and made it possible to carry out the first systematic comparisons between the Ulysses solar wind measurements and quantitative white-light observations of the solar corona. This paper summarize…
RS CVN Stars in the AAVSO Photoelectric Photometry Program
Percy, John R.; Soondarsingh, Devi; Velocci, Vince
We report V Photometry of three RS CVn stars--HK Lac, SZ Psc, and Lambda And--from the AAVSO photoelectric photometry program, and from transformed Hipparcos photometry, over 3500 days. Eighteen photoelectric photometry observers contributed to this project. The stars vary on periods of days to weeks, due to rotation of a spotted photosphere. The …
Luminosity calibration for OB stars from Hipparcos trigonometric parallaxes
Beshenov, G. V.; Loktin, A. V.
Hipparcos trigonometric parallaxes and observational data for open clusters are used to determine the absolute magnitudes MV of O and B stars of various spectral subtypes and luminosity classes, including those with broadened lines and hydrogen emission lines. The same data are used to derive a relation between MV and the ind…
Preliminary two-point observations of the mid-altitude cusp by Cluster PEACE and FGM
Coates, A. J.; Wilson, R. J.; Fazakerley, A. N. +8 more
On 1 October 2000, Cluster spacecraft Samba (Cluster 3) and Tango (Cluster 4) made an outbound crossing of the northern mid-altitude (4.7 RE) cusp region, moving roughly parallel to the noon meridian. We present preliminary observations from this interval made by the PEACE and FGM instruments. The interplanetary magnetic field at the magnetopause …
Research Note Nice Observatory CCD measurements of visual double stars (3rd series)
Gili, R.; Salaman, M.; Morlet, G.
We present the measurements of 58 visual double stars made in 1999 and 2000 with the 50 cm refractor of the Nice Observatory and attached CCD camera, using an algorithm based on the adjustment of a tridimensional mathematical surface (Table 1). 2 new binaries discovered by Hipparcos were measured.
Surface Brightness--Color Relation for Eclipsing Binaries with ubvy Photometry
Semeniuk, Irena
The relation between visual surface brightness and (b-y)_0 color index is constructed for eclipsing binaries with Hipparcos parallaxes and photometry in the Stromgren four-color ubvy system. The relation is consistent with the Popper relation derived for stars with angular diameters obtained mainly from interferometry or from the lunar occultation…
Inhomogeneity in the solar core
Gough, D. O.
In recent years, normal-mode helioseismology has shown that the spherically averaged sound-speed distribution throughout the solar interior is in remarkable agreement with suitable standard solar models. This implies that any deviation of the theoretical models from the Sun has only a very small influence on the oscillation frequency spectrum (exc…