Physical parameters of a mid-latitude streamer during the declining phase of the solar cycle

Abstract

Context. Investigating the physical properties of solar coronal streamers is important for understanding their role in the global magnetic structure of the extended solar atmosphere, as well as in the generation of the slow solar wind. Aims. We hope to contribute as completely as possible to the ongoing SOHO instruments campaign devoted to the study of the physical characteristics of coronal streamers at various heliocentric distances. Methods. We analyzed ultraviolet H i Lyα and O vi resonance doublet lines observed by UVCS/SOHO in a narrow, mid-latitude streamer structure along different lines of sight during a week in May 2004 and made nearly simultaneous white-light polarized brightness measurements from the LASCO/SOHO C2 coronagraph. Results. Electron densities and temperatures, H i and O vi kinetic temperatures, and outflow velocities were derived from the line