Coronal densities, temperatures, and abundances during the 2019 total solar eclipse: The role of multiwavelength observations in coronal plasma characterization

Electron densities ranged from log N (e) [cm(-3)] = 8.4 near the limb to 7.2 at R (0) = 1.3. EIS spectra indicate that the temperature distribution above the west limb is near isothermal at around 1.3 MK, while that on the east has an additional higher-T component. The AIR-Spec radiances in Si x and S xi, as well as the AIA data in the 171, 193, and 211 angstrom bands, are consistent with the EIS results.

EIS and AIR-Spec data indicate that the sulfur abundance (relative to silicon) is photospheric in both regions, confirming our previous results of the 2017 eclipse. The AIA data also indicate that the absolute iron abundance is photospheric. Our analysis confirms the importance of the diagnostic potential of the NIR wavelength range and that this important wavelength range can be used reliably and independently to determine coronal plasma parameters.