UVCS Observations of a High Latitude Streamer From 2-11 November 1999
Abstract
A high latitude coronal streamer was observed with the Ultraviolet Coronagraph Spectrometer UVCS on SOHO for ten days during the period 2 - 11 November 1999. The streamer was formed above a filament channel on the disk and, at the start of the observations, was located on the east limb at a position angle of about 150 deg. During the following ten days the streamer moved across the face of the Sun andand presented different aspect angles to the observed line of sight. We compare UVCS measurements of intensities and line widths of H Ly-alpha and O VI profiles obtained from 1.5 to 3.0 solar radii with equatorial streamer observations made near solar minimum. This work demonstrates that geometry effects are important when interpreting spectroscopic observations of coronal structures. In the future these observations will be used to model ion velocity distributions and outflow velocities in these high latitude streamer structures. This work is supported in part by NASA under grant NAG5-7822 to the Smithsonian Astrophysical Observatory, by the Italian Space Agency, and by Swiss funding agencies.
- Publication:
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AGU Spring Meeting Abstracts
- Pub Date:
- May 2000
- Bibcode:
- 2000AGUSM..SH42A04S
- Keywords:
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- Solar Corona;
- Coronal Streamers;
- UV spectroscopy