Yunnan Observatories of the Chinese Academy of Sciences researchers observed and verified for the first time that the coronal wave train totally reflected at the coronal hole boundary. It provides essential evidence for the essence of the coronal wave.
The study was published in Astronomy and Astrophysics. The highly structured corona is an inhomogeneous and anisotropic medium full of hot magnetized plasma. Waves often encounter regions where physical parameters vary considerably during propagation.
Since these regions have fast fast-mode magneto sonic wave velocities. Waves encountering these regions are often affected and exhibit true wave properties, such as refraction, reflection and transmission. Total reflection has not yet been detected, as an essential feature of the fluctuation theory.
Scientists analyzed a coronal wave train excited from the eastern edge of the Sun using high spatial and temporal imaging observations.
The critical angle for total reflection was 38 degrees. It is obtained by combining the differential emission measure (DEM) method with the electron density ratio inside and outside the coronal hole boundary. The incident angle was 33°.
The total reflection observed in this study further enriches the characteristics of the interaction between the coronal wave and coronal hole. This study provides observational evidence for the true wave theory of coronal waves.