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The dynamical nature of the coronal streamer belt
Wang, Y. -M.
SOHO/LASCO observations of the white-light corona have revealed a number of remarkable small-scale phenomena, including plasma blobs that are ejected continually from the cusps of streamers, fine raylike structures that pervade the streamer belt, and ubiquitous inflows during times of high solar activity. We discuss the implications of these obser…
Transition region quiet sun velocity field evolution
Vial, J. -C.; Wilhelm, K.; Curdt, W. +3 more
The UV/EUV SUMER spectrometer aboard SOHO can record profiles of lines emitted by elements at different stages of ionization corresponding to several temperatures within the transition region temperature range. During the solar cycle minimum in July 1996, we were able to observe the quiet Sun during five consecutive days. From the line positions w…
The NICMOS observational program: some personal examples
Thompson, Rodger I.
This paper reviews a few of the author's observational programs with the Near Infrared Camera and Multi-Object Spectrometer on the Hubble Space Telescope. These programs are taken as being partially representative of the very large body of observations carried out by NICMOS in both General Observer and Guaranteed Time Observer scientific programs.
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 …
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…
Cassini/VIMS observations of the moon
Sotin, C.; Brown, R. H.; Baines, K. H. +19 more
In this paper, we present preliminary scientific results obtained from the analysis of VIMS (Visible and Infrared Mapping Spectrometer) lunar images and spectra. These data were obtained during the Cassini Earth flyby in August 1999. Spectral ratios have been produced in order to derive lunar mineralogical maps. Some spectra observed at the north-…
Lyman α intensities in a polar coronal hole from a 2D model
Poletto, G.; Noci, G.; Nicolosi, P. +1 more
We simulate the coronal H I Lyman α intensity for heliocentric distances between 1.5 and 2.5 R⊙, and latitudes between 90° (North pole) and 30°, making use of a 2D semiempirical coronal hole model. Observations are made with the UltraViolet Coronagraph Spectrometer (UVCS) on board the ESA-NASA solar satellite SOHO (SOlar and Heliospheri…
Variation of acoustic mode centroid frequencies over the solar cycle
Chaplin, W. J.; Elsworth, Y.; Appourchaux, T. +2 more
Together with a brief historical overview, we use high-quality helioseismic data collected by three different observational programmes during the declining phase of activity cycle 22, and a substantial portion of the rising phase of the current cycle (23), to study the phenomenological nature of the cycle-induced (centroid) eigenfrequencies. Our a…