Temporal Observations of the λ5303 Emission Line Profile During the 74 Minute Totality from the Concorde SST at the 30 June 1973 Total Solar Eclipse: Preliminary Intensity Variations Above an Active Region

Abstract

(Nature). Apparatus was flown aboard the French-British Concorde SST to obtain high resolution emission line intensity profiles during the 30 June 1973 total solar eclipse. A prime objective was to obtain profiles that could be used to determine the presence in the Fe xiv coronal emission line, 530.3 nm, of the 300 s periodicity such as is observed in the photosphere and chromosphere. The long totality duration of 74 min on the French Concorde 001 provided a unique opportunity for this study. At the 55000 ft cruise altitude weather influences are negligible, scattered light background reduced and seeing conditions excellent. The instrumentation included a high resolution pressure scanned Fabry-Perot interferometer and high resolution recordind. This instrumentation was perfected in earlier Los Alamos Scientific Laboratory solar eclipse flights since 1965 (Liebenberg, 1965, 1967; Hoffman et al., 1970). A 12 cm aperture window and 7.7 cm aperture f/13 telescope were designed to optimize the use of the available space as shown in Figure 1.