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The purpose of this paper is to explore the observed physical characteristics of the solar corona streamer belt from 1996 June 1 to August 5. The UV spectral data was collected by the Ultraviolet Coronagraph Spectrometer (UVCS) instrument on board the Solar and Heliospheric Observatory (SOHO) spacecraft. From this data the abundances of oxygen, silicon, and magnesium were determined on an almost daily basis during this time period at both the west and east limbs. The streamer belt was composed of both active and quiescent streamers, which allows for the comparison of these two categories of magnetic field structures. The depletion of these three elemental abundances in the core of quiescent streamers was found, as in previous observations. The variance in abundance with solar rotation was investigated as a consequence of the long time frame considered here. The first ionization potential (FIP) effect was present in the data, and the danger of exploring this phenomena by the traditional FIP bias was also covered. A comparison with in situ elemental abundance data from the Charge, Element, and Isotope Analysis System (CELIAS) instrument on SOHO provides evidence suggesting that active-region streamers and the outer '' leg '' structural component of quiescent streamers are definite contributors to the slow solar wind.

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In this paper we analyze SOHO Ultraviolet Coronagraph Spectrometer (UVCS) observations of the sungrazing comet C/2001 C2, a member of the Kreutz family, observed on 2001 February 7 at heliocentric distances of 4.98 and 3.60 R . This comet apparently went through sequential fragmentation events along its path: further indication of fragmentation processes is provided by UVCS observations, which show the presence of two separate tails in the 4.98 R data set, which we interpret as two fragments unresolved by LASCO images, one of which sublimates before reaching 3.60 R . The cometary hydrogen Ly signal, decaying exponentially with time, has been interpreted in terms of the H 2 O outgassing rate and the interactions of coronal protons with atoms created by the photodissociation of water. However, one of the fragments shows an additional Ly contribution, constant with time, which adds to the temporally decaying signal. This contribution has been ascribed to the sublimation of pyroxene dust grains, whose end products neutralize coronal protons via charge exchange processes. Hence, the two fragments have different composition; differences throughout the comet body may have been the primary cause for the comet fragmentation.