Corona’r haul: Astudiaeth o strwythur atmosffer yr haul (The sun's corona: A study of the structure of the sun's atmosphere)

The knowledge we have about the sun’s corona is based on observations made from afar. It is impossible, therefore, to speculate about the three-dimensional structure of the corona directly. This article outlines the history of the study of the structure of the corona, and describes new techniques which for the first time enable us to know the structure of the corona in detail. A description is given of the change in the structure over the life cycle of the sun, together with new information about the connection between the magnetic field and coronal density and new results concerning the rotation rates of the corona. The results show that knowledge about the corona can be greatly increased by applying new tomography techniques, enabling and stimulating further studies of the corona in years to come.