Red line Fe X 637.4 nm image

Except the "Coronium" green line, another prominent coronal line is the red line 637.4 nm of 9× ionized iron. This radiation visualizes "cooler" coronal structures of about 800 000 K. The red color of the image is precisely computed so the color for the human vision is the same as the color of the 637.4 nm light. The coronal structures are even better visible in this B&W negative image.

Date31. 07. 1981
Time2nd contact 02:59:11 UT, 3rd contact 03:00:58 UT
Total eclipse duration 1 min 58 s
PlaceBratsk, Siberia, Russia
CoordinateE 101° 21' 40'', N 55° 58' 48'', altitude 410 m
ConditionsDense cirrus clouds
OpticsTwo identical refractors of 130 mm diameter, 1950 mm focal length on one paralactic mount equipped with polarizer and narrow-band filters 530.3 nm (0.2 nm half-width) resp. 637.4 nm (0.3 nm half-width) of B-13 type fy. Baird Atomic.
FilmFomapan N30 (6×6 cm format)
Exposure25 s
ProcessingRed line and green line image were aligned by means of phase correlation on Moon (images were taken simultaneously) and processed by means of Corona software.
Image processing by Miloslav Druckmüller
ScannerEpson Perfection V750 PRO
SoftwareSofo ACC 6.0 with Match II module, Corona 4.0
OrientationThe image must be rotated approx. 53° anti-clockwise to achieve the standard orientation i. e. North up and East left.
Copyright© 1981 Július Sýkora, © 2007 Miloslav Druckmüller

Miloslav Druckmüller
Institute of Mathematics, Faculty of Mechanical Engineering
Brno University of Technology, Czech Republic
Page last update: 8.3.2008