Prominences and chromosphere - SOHO EIT 30.4 nm composite

A single image taken shortly before the third contact in visible light by Libor Šmíd (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. SOHO spacecraft UV image 30.4 nm He II is shown right. Even if the radiation wavelength of SOHO image is about 22 times shorter and therefore the SOHO image shows structures of gas with significantly higher temperature, there is high correspondence between structures in both images. It is clearly visible on the composite image (middle). The bigger version of composite image further more illustrates that the Moon is of bigger angular size than the Sun.
Click on the following reference to display the same image in the maximum quality (1.0 MB, PNG format).

Date11. 08. 1999
Time10:23:42 UT
PlaceFrance, between Amiens and Beauvais, about 100 km northern from Paris.
CoordinateN 49° 38', E 2° 09'
ConditionsThin high clouds
OpticsRefractor Zeiss AS100/1000 mm with teleconverter 1.5×
FilmKodak Elite chrome 200
Exposure1/500 s
ProcessingOriginal color image of the prominences and the chromosphere (left) taken several seconds before the third contact was with subpixel precision matched with SOHO EIT 30.4 nm He II image (right) taken at 11:14 UT and finally composite was made (middle).
Image processing by Miloslav Druckmüller
ScannerNikon LS-2000
SoftwareSofo ACC 5.0 with Match II module
OrientationThe image must be rotated 20.51° clockwise to achieve the standard orientation (N top, E left) in heliocentric coordinate system
Copyright© 1999 Libor Šmíd, © 2004 Miloslav Druckmüller


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