Polarization in astronomy

Subsequently, Jesse Greenstein and Leverett Davis, Jr. developed theories allowing the use of polarization data to trace interstellar magnetic fields.

Circular polarization is mainly due to transmission and absorption effects in strongly magnetic regions of the Sun's surface.

As a result, polarization of the scattered photons is also modified providing a diagnostics tool for understanding stellar magnetic fields.

[2] Polarization is also present in radiation from coherent astronomical sources due to the Zeeman effect (e.g. hydroxyl or methanol masers).

It has been suggested that astronomical sources of polarised light caused the chirality found in biological molecules on Earth.