Observations from total solar eclipses are used to measure the shape of the Sun’s magnetic field.

IfA graduate student Benjamin Boe conducted a new study that used total solar eclipse observations to measure the shape of the coronal magnetic field with higher spatial resolution and over a larger area than ever before. The results were published in the Astrophysical Journal on June 3.

The corona is most easily seen during a total solar eclipse — when the moon is directly between the Earth and Sun, blocking sunlight. Significant technological advances in recent decades have shifted a majority of analysis to space-based observations at wavelengths of light not accessible from the ground, or to large ground-based telescopes such as the Daniel K. Inouye Solar Telescope on Maui. Despite these advances, some aspects of the corona can only be studied during total solar eclipses.

Boe was advised by UH Manoa Astronomy Professor Shadia Habbal, a coronal research expert. Habbal has led a group of eclipse chasers, the Solar Wind Sherpas making scientific observations during solar eclipses for more than 20 years. These observations have led to breakthroughs in unveiling some of the secrets of the physical processes defining the corona.

«The corona has been observed with total solar eclipses for well over a century, but never before had eclipse images been used to quantify its magnetic field structure,» explained Boe. «I knew it would be possible to extract a lot more information by applying modern image processing techniques to solar eclipse data.»

Boe traced the pattern of the distribution of magnetic field lines in the corona, using an automatic tracing method applied to images of the corona taken during 14 eclipses the past two decades. This data provided the chance to study changes in the corona over two 11-year magnetic cycles of the Sun.

Story Source: Materials provided by University of Hawaii at Manoa. Note: Content may be edited for style and length.