Analysis of the stellar occultations during the unprecedented long-duration flare

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F24%3A00597853" target="_blank" >RIV/67985815:_____/24:00597853 - isvavai.cz</a>

Result on the web

<a href="https://hdl.handle.net/11104/0355698" target="_blank" >https://hdl.handle.net/11104/0355698</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/2041-8213/ad6c06" target="_blank" >10.3847/2041-8213/ad6c06</a>

Result language

angličtina

Original language name

Analysis of the stellar occultations during the unprecedented long-duration flare

Original language description

In strong stellar and solar flares, flare loops typically appear during the decay phase, providing an additional contribution to the flare emission and, possibly, obscuring the flare emission. Superflares, common in active, cool stars, persist mostly from minutes to several hours and alter the star's luminosity across the electromagnetic spectrum. Recent observations of a young main-sequence star reveal a distinctive cool loop arcade forming above the flaring region during a 27 hr superflare event, obscuring the region multiple times. Analysis of these occultations enables the estimation of the arcade's geometry and physical properties. The arcade's size expanded from 0.213 to 0.391 R * at a speed of approximately 3.5 km s-1. The covering structure exhibited a thickness below 12,200 km, with electron densities ranging from 1013 to 1014 cm-3 and temperatures below 7600 K, 6400 K, and 5077 K for successive occultations. Additionally, the flare's maximum emission temperature has to exceed 12,000 K for the occultations to appear. Comparing these parameters with known values from other stars and the Sun suggests the structure's nature as an arcade of cool flare loops. For the first time, we present the physical parameters and the reconstructed geometry of the cool flare loops that obscure the flaring region during the gradual phase of a long-duration flare on a star other than the Sun.

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/GF22-30516K" target="_blank" >GF22-30516K: Superflares: Their origins and connection with planets</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

Astrophysical Journal Letters

ISSN

2041-8205

e-ISSN

2041-8213

Volume of the periodical

972

Issue of the periodical within the volume

1

Country of publishing house

US - UNITED STATES

Number of pages

9

Pages from-to

L11

UT code for WoS article

001297491700001

EID of the result in the Scopus database

2-s2.0-85202495878