Onset of penumbra formation

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F24%3A00586943" target="_blank" >RIV/67985815:_____/24:00586943 - isvavai.cz</a>

Alternative codes found

RIV/00216208:11320/24:10478916

Result on the web

<a href="https://hdl.handle.net/11104/0354765" target="_blank" >https://hdl.handle.net/11104/0354765</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/202348764" target="_blank" >10.1051/0004-6361/202348764</a>

Result language

angličtina

Original language name

Onset of penumbra formation

Original language description

Context. Fully fledged penumbrae have been widely studied both observationally and theoretically. Yet the relatively fast process of penumbra formation has not been studied closely with high spatial resolution. Aims. We investigate the stages previous to and during the formation of penumbral filaments in a developing sunspot. Methods. We analysed Milne-Eddington inversions from spectro-polarimetric data of the leading sunspot of NOAA 11024 during the development of its penumbra. We focused on selected areas of this protospot in which segments of penumbra develop. Results. We find that few types of distinctive flow patterns develop at the protospot limb and centre sides previous to penumbra formation. The flow in the centre side is often characterised by a persistent (> 20 min) inflow-outflow pattern extending radially over 4 arcsec at the direct periphery of the protospot umbra. This inflow-outflow system often correlates with elongated granules, as seen in continuum intensity maps, and is also coupled with magnetic bipolar patches at its edges, as seen in magnetograms. The field is close to horizontal between the bipolar patches, which is indicative of its possible loop configuration. All of these aspects are analogous to observations of magnetic flux emergence. In the protospot limb side, however, we observed a mostly regular pattern associated with small granules located near the protospot intensity boundary. Locally, an inflow develops adjacent to an existing penumbral segment, and this inflow is correlated with a single bright penumbral filament that is brighter than filaments containing the Evershed flow. All investigated areas at the centre and limb side eventually develop penumbral filaments with an actual Evershed flow that starts at the umbral boundary and grows outwards radially as the penumbral filaments become longer in time.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

<a href="/en/project/GF23-07633K" target="_blank" >GF23-07633K: Unveiling the principles of solar magneto-convection</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2024

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Astronomy & Astrophysics

ISSN

0004-6361

e-ISSN

1432-0746

Volume of the periodical

686

Issue of the periodical within the volume

June

Country of publishing house

FR - FRANCE

Number of pages

9

Pages from-to

A112

UT code for WoS article

001237764300006

EID of the result in the Scopus database

2-s2.0-85195312711