Eclipse Observations of Coronal Emission Lines.

Abstract. Coronal spectra during the total solar eclipse of 1980 February 16, were obtained in the 6374Å [Fex] line using a multislit spectrograph. These spectra have a dispersion of 2·5 Å mm–1. The observed line profiles from 1·1 to 1·7 R with a spatial resolution of 10 × 22 arcsec2, give half-widths that vary between 0·6 Å and 2·4Å. A large number of locations have half-widths around 1·3 Å corresponding to a temperature of 4·6 × 106 K. If temperature of the order of 1·3 × 106 Κ are typical of the regions that emit [Fex], then turbulent velocities of ~ 30 km s–1 need to be invoked for the enhanced line broadening. The line-of-sight velocities measured range between +14 km s–1 to –17 km s–1. Most of the locations have velocities less than ±5 km s–1. From these observations we conclude that corona does not show any localized differential mass motion and that it co-rotates with the photospheric layers deeper down. Key words: Solar corona — red coronal line — turbulent velocities — rotation of solar coron