Einstein's Eclipse, Colorized

April 05, 2021


Image Creator: ESO/Landessternwarte Heidelberg-Königstuhl/F. W. Dyson, A. S. Eddington, & C. Davidson, P. Horálek/Institute of Physics in Opava, M. Druckmüller
Summary Author: Petr Horálek 

The total solar eclipse shown above was observed on May 29, 1919, from Sobral, Brazil. Using a digital scan of this eclipse from one copy of a photographic plate, part of the Heidelberg Digitized Astronomical Plates (HDAP) project funded by the Klaus Tschira Foundation, it was possible to reconstruct the solar corona and also structures of the huge prominence of this scientifically important eclipse that helped confirm Einstein’s General relativity. In order to so, however, we needed to separate real details from scratches and dust on the scan and focus on sub-threshold information hidden in a high dynamic range of the original photograph.

Since the eclipse was photographed on a classical photographic plate and the scan was saved in high quality, it was possible to apply basic postprocessing methods, which are nowadays used for digital photography, and also apply special Noise Adaptive Fuzzy Equalization software developed by Professor Miloslav Druckmüller. Despite very inhomogeneous exposure of the plate and non-perfect removal of artifacts, fine details in the solar corona of the 1919 eclipse have been preserved and revealed.

The most notable feature is the huge prominence located close to the equatorial area of the Sun -- the largest prominence ever captured during a total solar eclipse. Also of note are structures typical of the uneven solar magnetic field. When such structures became more obvious, by defining the basic colors of known phenomena in the image (prominence, solar corona), it was then possible to colorize the final result and thus for the first time show this famous eclipse in a way never seen before.