A distinct magnetic property of the inner penumbral boundary II. Formation of a penumbra at the expense of a pore

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F17%3A00479157" target="_blank" >RIV/67985815:_____/17:00479157 - isvavai.cz</a>

Result on the web

<a href="http://hdl.handle.net/11104/0275153" target="_blank" >http://hdl.handle.net/11104/0275153</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/201628547" target="_blank" >10.1051/0004-6361/201628547</a>

Result language

angličtina

Original language name

A distinct magnetic property of the inner penumbral boundary II. Formation of a penumbra at the expense of a pore

Original language description

Here, we aim to study the development of a penumbra initiated at the boundary of a pore, where the penumbra colonises the entire pore ultimately. We have used Hinode/SOT G-band images to study the evolution of the penumbra. Hinode /SOT spectropolarimetric data were used to infer the magnetic field properties in the studied region. The penumbra forms at the boundary of a pore located close to the polarity inversion line of NOAA10960. As the penumbral bright grains protrude into the pore, the magnetic flux in the forming penumbra increases at the expense of the pore magnetic flux. Consequently, the pore disappears completely giving rise to an orphan penumbra. At all times, the vertical component of the magnetic field (B-ver) in the pore is smaller than B-ver found on stable umbra-penumbra boundaries (B-ver-stable), which is around 1.8 kG. Our findings are in an agreement with the need of B-ver-stable for establishing a stable umbra-penumbra boundary: while B-ver in the pore is smaller than B-ver-stable, the protrusion of penumbral grains into the pore area is not blocked, a stable pore-penumbra boundary does not establish, and the pore is fully overtaken by the penumbral magneto-convective mode. This scenario could also be one of the mechanisms giving rise to orphan penumbrae.

Czech name

—

Czech description

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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/GA14-04338S" target="_blank" >GA14-04338S: Physical nature of sunspots</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2017

Confidentiality

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

Name of the periodical

Astronomy & Astrophysics

ISSN

1432-0746

e-ISSN

—

Volume of the periodical

597

Issue of the periodical within the volume

January

Country of publishing house

FR - FRANCE

Number of pages

4

Pages from-to

"A60/1"-"A60/4"

UT code for WoS article

000392392900037

EID of the result in the Scopus database

2-s2.0-85007524220