Corona - SOHO EIT/MDI magnetogram composite

The information about magnetic field polarity is very important for understanding the structure of coronal features. Therefore I created images presented on this page. The B&W version of previous image was colored using colors derived from the color version of SOHO MDI magnetogram (top left). The resulting image is shown on the top right. The orange color represents positive polarity, the blue one represents negative polarity. The color saturation is proportional to the magnetic field intensity. As the polarity of weak magnetic fields is not easily traceable from the resulting image I created another version of the image with the color saturation increased 4×.
Click on the image or on the following reference to display the higher resolution image version (942 KB, PNG format).

Date08. 04. 2005
Time2nd contact 21:15:05 UT, 3rd contact 21:15:37 UT
SOHO EIT 19.5 nm image 21:23:37 UT
SOHO EIT 30.4 nm image 21:29:23 UT
SOHO MDI magnetogram 21:28 UT
PlacePacific ocean aboard the MV Galapagos Legend (about 2100 km west from the Galapagos)
Coordinate1° 19.554' S, 109° 30.190' W
ConditionsClear sky, altitude of the Sun above the horizon 60°
OpticsCanon 500mm f/4 IS lens
CameraCanon EOS 1Ds Mark II digital camera
Exposure1/2000 s - 1/15 s
ProcessingComposition of 7 eclipse images, 2 SOHO EIT images a SOHO MDI magnetogram. Eclipse images were aligned by means of phase correlation, calibrated and composed using a new, for this purpose newly developed, software LDIC 1.0 and then processed using Corona 3.0 in order to visualize coronal structures. Composition with SOHO images and the final processing were done in ACC 6.0 software.
Image processing by Miloslav Druckmüller
SoftwarePhaseCorr 3.0, LDIC 1.0, Corona 3.0, Sofo ACC 6.0
NoteFile names of used SOHO EIT images:
  efz20050408_212337 (19.5 nm Fe XII)
  efz20050408_212923 (30.4 nm He II)
OrientationThe image has the standard orientation i.e. North top, East left
More infoOriginal set of images
Copyright© 2005 Miloslav Druckmüller, Fred Espenak


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