Affiliation

Astronomical Institute of the Czech Academy of Sciences, Ondřejov, Czech Republic

Main category

Natural Sciences (Astrophysics and Astrononmy)

Abstract

Bright heads of penumbral filaments, penumbral grains (PGs), move toward the umbra (inwards) in the inner penumbra and away from the umbra (outwards) in the outer penumbra. In a model by Tiwari et al. (2013, A&A 557, A25), penumbral filaments are magnetoconvective cells distributed everywhere in the penumbra and embedded in a background magnetic field whose inclination increases with the distance from the umbra. Sobotka & Puschmann (2022, A&A 662, A13) have shown that PGs motions change their orientation from inwards to outwards in the middle penumbra and their outward speed gradually increases with distance in the outer penumbra. We use spectropolarimetric observations of sunspot penumbrae to compare magnetic inclinations inside PGs with those in their surroundings. We show that inward-moving PGs mostly have magnetic inclination larger than that in the surroundings and the inclination in outward-moving PGs is usually smaller than the surrounding one.

Link this poster

https://science-media.org/poster/152