Observations of Chromosphere and Solar Corona During Annular Eclipse of February 26, 2017

June 15, 2017

Ase_2017_comp-171 (2)

Photographers: Miloslav Druckmüller; Petr Horálek
Summary Authors: Petr Horálek; Miloslav Druckmüller

During the annular solar eclipse of February 26, 2017, using photographic film, we were able to contend successfully with the Sun's extremely high dynamic range (ratio of approximately 1:5,000,000) to reveal the solar chromosphere and even a faint hint (pink) of the corona. The resultant images of the beginning and end phases of the eclipse we blended with data from NASA's Solar Dynamics Observatory (SDO), Atmospheric Imaging Assembly (AIA). By utilizing a new image processing method, known as Noise Adaptive Fuzzy Equalization (NAFE), we were able to get even more details from AIA 171 and prepared this unique image blending what was seen from the ground at approximately the same time as the satellite data was acquired. The NAFE enhancement method produces artifact-free images and thus allows visualization of fine structures in the imagery acquired from NASA's SDO AIA 171 sensors.

Photo Details: Image shows the Sun from ground observation of the annular solar eclipse on classical film and data from SDO AIA 171 at nearly the same time. The eclipse was captured on FujiColor Superia 200 with a Canon ESO 3000 camera and Skywatcher MAK 90 mm/1250 mm lenses. The post-processing of the film, which included a scattering mask algorithm, reduction of global contrast and additive noise, revealed the annular eclipse in fascinating detail and the most natural view ever photographed, due to the high dynamic range of classical film. Then we used data from SDO AIA 171, A closest to the time of the ground observation, sharpened by Noise Adaptive Fuzzy Equalization (NAFE) software, provided by Professor Miloslav Druckmüller, and blended the captured chromosphere and photosphere during the eclipse with the sharpened satellite image.