Quasi-periodic pulsations in flares of UV Ceti-type stars

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F24%3A00646106" target="_blank" >RIV/67985815:_____/24:00646106 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/68378271:_____/24:00646106

Výsledek na webu

<a href="http://dx.doi.org/10.26119/VAK2024.079" target="_blank" >http://dx.doi.org/10.26119/VAK2024.079</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.26119/VAK2024.079" target="_blank" >10.26119/VAK2024.079</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Quasi-periodic pulsations in flares of UV Ceti-type stars

Popis výsledku v původním jazyce

Quasi-periodic pulsations (QPPs) were observed in the light curves of solar and stellar flares. The number of stellar QPP events is quite small (213 in 2021), which is why they are interesting. QPPs can be used to investigate the properties of flare regions and they are still a problem for flare models. QPPs were identified in stellar flares across a wide range of wavelengths, from radio to X-rays. In the optical band they are searched mainly in the Kepler and TESS data. The periods of QPPs detected from these sources are longer (tens of minutes) than from the high cadence data. Observations with the 6-m telescope BTA and the MANIA complex, as well as the space observatory GALEX, reveal QPP periods of only tens of seconds. On the other hand, solar flares are typically weaker (energies <<10^32 erg) than stellar flares, that possibly makes them more difficult to detect in white light. Our data on 157 flares of dM-type stars (EV Lac, Wolf 359, Wolf 424, V577 Mon, and UV Ceti), obtained from 70 hours of observations with the BTA telescope in U-band with microsecond time resolution, represents a significant breakthrough in the search for QPPs in stars. In this paper, we present the characteristics of 13 QPPs found in 44 flares. The QPPs have periods ranging from 6 to 107 seconds, and were identified using both Fourier transform and empirical mode decomposition methods. We classify the observed QPPs based on the evolution of their oscillation envelopes and fractional flux amplitudes.

Název v anglickém jazyce

Quasi-periodic pulsations in flares of UV Ceti-type stars

Popis výsledku anglicky

Quasi-periodic pulsations (QPPs) were observed in the light curves of solar and stellar flares. The number of stellar QPP events is quite small (213 in 2021), which is why they are interesting. QPPs can be used to investigate the properties of flare regions and they are still a problem for flare models. QPPs were identified in stellar flares across a wide range of wavelengths, from radio to X-rays. In the optical band they are searched mainly in the Kepler and TESS data. The periods of QPPs detected from these sources are longer (tens of minutes) than from the high cadence data. Observations with the 6-m telescope BTA and the MANIA complex, as well as the space observatory GALEX, reveal QPP periods of only tens of seconds. On the other hand, solar flares are typically weaker (energies <<10^32 erg) than stellar flares, that possibly makes them more difficult to detect in white light. Our data on 157 flares of dM-type stars (EV Lac, Wolf 359, Wolf 424, V577 Mon, and UV Ceti), obtained from 70 hours of observations with the BTA telescope in U-band with microsecond time resolution, represents a significant breakthrough in the search for QPPs in stars. In this paper, we present the characteristics of 13 QPPs found in 44 flares. The QPPs have periods ranging from 6 to 107 seconds, and were identified using both Fourier transform and empirical mode decomposition methods. We classify the observed QPPs based on the evolution of their oscillation envelopes and fractional flux amplitudes.

Druh

D - Stať ve sborníku

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2024

Kód důvěrnosti údajů

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

Název statě ve sborníku

Proceedings of the Modern astronomy: from the Early Universe to exoplanets and black holes

ISBN

978-5-369-02160-6

ISSN

—

e-ISSN

—

Počet stran výsledku

4

Strana od-do

421-424

Název nakladatele

Special Astrophysical Observatory of the Russian Academy of Sciences

Místo vydání

Arkhyz

Místo konání akce

Nizhny Arkhyz

Datum konání akce

25. 8. 2024

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

—