Some Belgian Friends at the ATT Essen (May 11, 2022); see this link for more pictures.
The Evershed effect is named after the British John Evershed and is the radial flow of gas across the photospheric surface of the penumbra of a sunspot from the inner border with the umbra towards the outer edge. Evershed discoverd this back in 1909 when working at the Kokaikanal Solar Observatory in the south of India. See also this video about the Evershed Effect. There is also an inverse Evershed flow (IEF) going in the opposite direction.
Ref. C. Beck and D. P. Choudhary 2020 ApJ 891 119 |