Prominences and chromosphere - SOHO EIT 30.4 nm Composite

A single image taken shortly after the second contact (left) shows the loop structure of the prominences and a lot of fine structures in the solar chromosphere. Hydrogen emission (H-alpha spectral line, 656 nm) is responsible for the red color of the chromosphere and of the prominences. About two minutes after the image was taken SOHO spacecraft made UV image 30.4 nm He II (middle). Even if the radiation wavelength of SOHO image is about 22× shorter and therefore shows structures of gas with significantly higher temperature there is surprisingly high correspondence between this structures which is worth studying. This correspondence can be studied on the pseudocolor composite image (right) or even better on the animation (MNG format) gradually displaying all mentioned images.
Click on the image or on the following reference to display the higher resolution image version (4.2 MB, PNG format).

Date 21. 06. 2001
TimeSecond contact 12:36:34 UT, third contact 12:41:10 UT
Total eclipse duration 4 min 36 s
PlaceAngola, near Sumbe (Ngunza)
CoordinateS 11° 07' 29'', E 13° 55' 51'', Alt. 168 m
ConditionsExcellent, clear sky
OpticsMertz - II, 1875/100 mm (VOD Turnov), siderostat off-axis configuration
CameraPENTAX 67 II, 6 × 7.5 cm format
Resolution1.314 arc sec / pixel - full resolution image version
2.629 arc sec / pixel - animation
FilmKodak Ektachrome 100 S Professional
ProcessingOriginal color image of the prominences and the chromosphere (left) taken several seconds after the second contact was with subpixel precision matched with SOHO EIT 30.4 nm He II image (middle) taken at 12:38:44 UT and finally pseudocolor composite was made (right).
Image processing by Miloslav Druckmüller
ScannerNikon LS 8000 (4000dpi resolution, RGB, 3 × 16 bit/pixel)
SoftwareSofo ACC 5.0 Scientific Image Analyzer with Match II Module
NoteSOHO EIT image file name: efz20010621_123844.fts
OrientationAll images have the standard orientation (N top, E left)
Copyright© 2001 Úpice Observatory, © 2001 ESA/NASA, © 2003 Miloslav Druckmüller


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