MACS for global measurements of the thermal electron temperature and the solar wind velocity in the solar corona during the total solar eclipse of 11 August 1999
The determination of the radial and latitudinal temperature and wind profiles of the solar corona is of immense importance in understanding the coronal heating mechanism and the dynamics of the coronal features. Cram (1976) provides the theory for the formation of the K-coronal spectrum and a method for determining the radial profile of the coronal temperature. A slit-based spectroscopic study was performed by Ichimoto et.al (1996) on the solar corona in conjunction with the total solar eclipse of 1994 to evaluate the temperature profiles of the solar corona. We have modified Cram's theory to incorporate the role of the solar wind in the formation of the K-corona and have identified both temperature and wind sensitive intensity ratios. We built MACS (Multi Aperture Coronal Spectrometer); a fiber optic based spectrograph to study the total solar eclipse of August 1999 in Elazig, Turkey. In this instrument one end of the twenty fiber optic tips at the focal plane of the telescope were positioned to see different radii and latitudes of the solar corona. The other ends of the fibers were vertically aligned and placed at the primary focus of the collimating lens of the spectrograph. By isolating the K-coronal spectrum and calculating the temperature and the wind sensitive intensity ratios we have simultaneously measured both the thermal electron temperatures and the solar wind velocities at some discrete locations on the solar corona.
AAS/Solar Physics Division Meeting #31
- Pub Date:
- May 2000