An unusual velocity field in a sunspot penumbra
Context. The photospheric Evershed flow is normally oriented radially outward, yet sometimes opposite velocities are observed not only in the chromosphere but also in the photospheric layers of the penumbra. Aims. We studied the velocity field in a special case of an active region with two mature sunspots, the lesser of which formed several days
Balthasar, H. et al.
Fecha de publicación:
12
2025