Solar corona up to 25 solar radii

Good observing conditions and the high number of acquired images (totally 98 images, 63 digital, 35 a on classical film) made possible to visualize the corona with acceptable contrast up to 12 solar radii. The next logical step was to compose the Earth-based images with the SOHO LASCO C3 coronograph image. The resulting image give us an unique opportunity to follow the coronal structures from the edge of solar disc up to at least 25 solar radii. The processing steps you can follow on this sequence: The bright points in the resulting images are stars. The original image contains not only stars, but also the impulse noise. This impulse noise was filtered out. In order to preserve stars, it was necessary to identify them before the filtering procedure. It was done by aligning and comparing two different SOHO images.
Click on the image or on the following reference to display the higher resolution image version (740 KB, PNG format).

Date29. 03. 2006
Time2nd contact 11:02:23 UT, 3rd contact 11:05:29 UT
SOHO LASCO C3 image 10:51 UT
PlaceNear Göreme, Cappadocia, Turkey
CoordinateE 34° 52.147', N 38° 39.390', alt. 1330 m
ConditionsGood, thin cirrus clouds out of the solar disk, strong wind, altitude of the Sun above the horizon 50°
OpticsD: Maksutov-Cassegrain MC 3M-5CA, 8/500 mm
A: Pentacon, 4/200mm
CameraD: Canon EOS 1D Mark II digital camera (ISO 100)
A: Minolta X 370 classical film camera
FilmA: Fujichrome Superia X-TRA 800
ExposureD: 1/1000 s - 8 s
A: 1/125 s - 1 s
ProcessingComposition of 98 images (63 D, 35 A) and SOHO LASCO C3 image. Images were aligned by means of phase correlation, composed using of LDIC 4.0 software, processed using Corona 4.0 in order to visualize coronal structures. Final processing was done using ACC 6.0 software.
Image processing by Miloslav Druckmüller and Hana Druckmüllerová
ScannerA: Nikon Super Coolscan 4000 ED (Multisample 16×)
SoftwarePhaseCorr 4.0, LDIC 4.0, Corona 4.0, Sofo ACC 6.0
NoteD: denotes equipment of Hana Druckmüllerová
A: denotes equipment of Martin Antoš
OrientationImage has standard orientation i. e. North up.
Copyright© 2006 Martin Antoš, Hana Druckmüllerová, Miloslav Druckmüller

Miloslav Druckmüller
Institute of Mathematics, Faculty of Mechanical Engineering
Brno University of Technology, Czech Republic
Page last update: 27.11.2019