Coronal structure

The corona during the total solar eclipse on July 22th, 1990 was of the structure typical for solar cycle maximum. The most interesting feature was large coronal hole in south polar region.

Click on the following reference to display the same image in the maximum quality (247 KB, PNG format).

Date22. 07. 1990
TimeSecond contact 03:03:06 UT, third contact 03:04:50 UT
Eclipse duration 104 s
PlaceRussia, Chukotka, Markovo village near Anadyr river
CoordinateE 170° 30' , N 64° 43'
ConditionsGood - altitude of the Sun 41° above the horizon
OpticsMerz 160 mm stopped down to 90 mm, focal length 1785 mm
FilmFortepan 400
Exposure1/125 s - 2 s
ProcessingSum of 7 images enhanced by means of adaptive kernel convolution. The original images are B&W, the color is added by image processing.
Image processing by Miloslav Druckmüller
ScannerNikon LS 8000 (4000dpi resolution, 16 bit/pixel)
SoftwareSofo ACC 6.0 Scientific Image Analyzer with Match II Module (final processing)
Corona 3.0 (coronal structure enhancement)
PhaseCorr 2.0 (rotation estimation - registration of images)
NoteThe graph above the table shows the average values of the relative number of sunspots in which the red arrow indicates the time of 1990 eclipse. Graph was created according to data from Sunspot Index Data Center, Brussels.
OrientationThis image has the standard orientation i.e. North on the top end East on the left
Copyright© 1990 Úpice Observatory, © 2004 Miloslav Druckmüller


Miloslav Druckmüller
Institute of Mathematics, Faculty of Mechanical Engineering
Brno University of Technology, Czech Republic
Page last update: 19.3.2007