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International Solar Cycle Studies [ISCS] Working Group 2: solar magnetic field variability - from the lower atmosphere through the inner corona
Harrison, Richard A.; Michels, Donald
This report is a summary of activities and plans relating to the International Solar Cycle Studies (ISCS) Working Group 2, which is concerned with solar magnetic field variability, from the lower atmosphere through the inner corona. Whilst the Working Group carries a rather general title, the activities are focusing on several well defined topics …
Intercalibration of SUMER and CDS on SOHO. II. SUMER Detectors A and B and CDS NIS: Erratum
Solanki, Sami K.; Wilhelm, Klaus; Schühle, Udo +6 more
Energetic particles during the first two years of SOHO science mission
Torsti, J.; Anttila, A.
Energetic particle intensities observed by ERNE instrument onboard SOHO spacecraft during the first two years of SOHO science mission have been analysed and compared to observations of IMP 8 satellite around two earlier sunspot minima. During an eight month period around the latest sunspot minimum, which occurred in October 1996, energetic particl…
Solving Olin Wilson's Mystery
Abt, Helmut A.
Wilson showed that G8-M1 dwarfs have a range of 0.30 mag in P-V color whereas the color range for earlier stars is 0.12 mag. He attributed the increased range for the later stars to differing hydrogen-to-metal ratios in the temperature region where most of the electrons come from the metals. I explored those stars using Hipparcos parallaxes and ph…
The synchrotron spectrum of the M87 jet
Leahy, J. P.; Macchetto, F. D.; Sparks, W. B. +2 more
We present 1998 HST observations which yield the first single-epoch spectrum of the M87 jet from 0.3 to 2.0 microns. The flattest optical spectra ( αo∼0.6, where F ν ∝ ν -α; comparable to αro) are found in two inner jet knots which contain the fastest superluminal components. Other knots have somewhat st…
Broadband Plasma Waves in the Magnetopause and Plasma Sheet Boundary Layers
Lakhina, G. S.; Tsurutani, B. T.; Pickett, J. S.
Intermediate-Brightness Equatorial Spectrophotometric Standards
Tereshchenko, V. M.
We have obtained spectral energy distributions for 41 7m 8m stars near the celestial equator (δ=±3°). The λλ3100 7600 Å spectral range is studied with a spectral resolution of 50 Å. The relative rms error in the visible is 1 2%, increasing to 3 5% towards the edges of the wavelength interval studied. All stars are referenced to a single standard, …
The Nature of the Double Star M40
Nugent, Richard L.
WNC 4 is listed as a double star in the literature dating back to 1869. Charles Messier catalogued this object as M40 in his famous list. Using new TYCHO-2 and other data, the minimum distance to the pair is found to be 170 +/- 70 pc. The new parallax and proper motion data failed to support any assumption that the two stars in the pair are gravit…
The Structure of the Planetary Nebula IC 2149: A Jet or an Edge-On Ring?
López, J. A.; Torrelles, J. M.; Miranda, L. F. +4 more
A set of optical and radio observations of the peculiar planetary nebula (PN) IC 2149 is presented. A bow-shock-like feature towards the NE edge is first detected with the VLA-A, and is also confirmed with HST archive images. Optical spectroscopy leads to apparently contradictory results, leaving this object as a unique case among the planetary ne…
The effect of instrument limitations on the derivation of plasma flows from energetic ion anisotropies, with an application to Ulysses observations at Jupiter
Cowley, S. W. H.; Kolesnikova, E.
Plasma velocities determined from the anisotropies of energetic ions via the Compton-Getting effect have been important in studies of magnetospheric flows, particularly with regard to the magnetospheres of Jupiter and Saturn. In this paper we consider a range of issues concerned with the practical limitations of such measurements, and their effect…