Investigation of emission lines of the solar corona of 10 July, 1972 using the Fabry-Pérot etalon

✍ Scribed by I. S. Kim; G. M. Nikolsky

• Publisher: Springer
• Year: 1975
• Tongue: English
• Weight: 847 KB
• Volume: 43
• Category: Article
• ISSN: 0038-0938
• DOI: 10.1007/bf00152359

✦ Synopsis

Coronal interferograms in the lines of Fe xiv 5303/~, He ~ 5876 A and Fe x 6374 A were obtained during the total solar eclipse of 10 July, 1972 (see Figure 2). He r emission was found in the chromosphere only. The upper limit of the D8 equivalent width in terms of the coronal continuous background is 0.013 A in the inner corona (r = 1.15 RO). The 2 6374 negative was taken with low contrast. The half width of 26374 is 1.0-1.08 A for a limited area of the corona (P =88-104 ~ r --1.30-1.44 R| A detailed photometry of the 5303/~ line was carried out and the behaviour of the half widths and equivalent widths were studied in different regions of the corona. The half width of 25303 increases with distance from the Sun's center in almost all the studied regions (1.2 R| ~< r ~ 1.7 R| This increase corresponds to an increase of the non-thermal velocities with a gradient of 1-2 km s -1 per 0.1 R o. The equivalent widths, expressed in the coronal continuous background intensity remain constant on the average.