Vše

Co hledáte?

Vše
Projekty
Výsledky výzkumu
Subjekty

Rychlé hledání

  • Projekty podpořené TA ČR
  • Významné projekty
  • Projekty s nejvyšší státní podporou
  • Aktuálně běžící projekty

Chytré vyhledávání

  • Takto najdu konkrétní +slovo
  • Takto z výsledků -slovo zcela vynechám
  • “Takto můžu najít celou frázi”

Stochastic light variations in hot stars from wind instability: finding photometric signatures and testing against the TESS data

Identifikátory výsledku

  • Kód výsledku v IS VaVaI

    <a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F21%3A00118998" target="_blank" >RIV/00216224:14310/21:00118998 - isvavai.cz</a>

  • Výsledek na webu

    <a href="https://doi.org/10.1051/0004-6361/202040148" target="_blank" >https://doi.org/10.1051/0004-6361/202040148</a>

  • DOI - Digital Object Identifier

    <a href="http://dx.doi.org/10.1051/0004-6361/202040148" target="_blank" >10.1051/0004-6361/202040148</a>

Alternativní jazyky

  • Jazyk výsledku

    angličtina

  • Název v původním jazyce

    Stochastic light variations in hot stars from wind instability: finding photometric signatures and testing against the TESS data

  • Popis výsledku v původním jazyce

    Context. Line-driven wind instability is expected to cause small-scale wind inhomogeneities, X-ray emission, and wind line profile variability. The instability can already develop around the sonic point if it is initiated close to the photosphere due to stochastic turbulent motions. In such cases, it may leave its imprint on the light curve as a result of wind blanketing.Aims. We study the photometric signatures of the line-driven wind instability.Methods. We used line-driven wind instability simulations to determine the wind variability close to the star. We applied two types of boundary perturbations: a sinusoidal one that enables us to study in detail the development of the instability and a stochastic one given by a Langevin process that provides a more realistic boundary perturbation. We estimated the photometric variability from the resulting mass-flux variations. The variability was simulated assuming that the wind consists of a large number of independent conical wind sectors. We compared the simulated light curves with TESS light curves of OB stars that show stochastic variability.Results. We find two typical signatures of line-driven wind instability in photometric data: a knee in the power spectrum of magnitude fluctuations, which appears due to engulfment of small-scale structure by larger structures, and a negative skewness of the distribution of fluctuations, which is the result of spatial dominance of rarefied regions. These features endure even when combining the light curves from independent wind sectors.Conclusions. The stochastic photometric variability of OB stars bears certain signatures of the line-driven wind instability. The distribution function of observed photometric data shows negative skewness and the power spectra of a fraction of light curves exhibit a knee. This can be explained as a result of the line-driven wind instability triggered by stochastic base perturbations.

  • Název v anglickém jazyce

    Stochastic light variations in hot stars from wind instability: finding photometric signatures and testing against the TESS data

  • Popis výsledku anglicky

    Context. Line-driven wind instability is expected to cause small-scale wind inhomogeneities, X-ray emission, and wind line profile variability. The instability can already develop around the sonic point if it is initiated close to the photosphere due to stochastic turbulent motions. In such cases, it may leave its imprint on the light curve as a result of wind blanketing.Aims. We study the photometric signatures of the line-driven wind instability.Methods. We used line-driven wind instability simulations to determine the wind variability close to the star. We applied two types of boundary perturbations: a sinusoidal one that enables us to study in detail the development of the instability and a stochastic one given by a Langevin process that provides a more realistic boundary perturbation. We estimated the photometric variability from the resulting mass-flux variations. The variability was simulated assuming that the wind consists of a large number of independent conical wind sectors. We compared the simulated light curves with TESS light curves of OB stars that show stochastic variability.Results. We find two typical signatures of line-driven wind instability in photometric data: a knee in the power spectrum of magnitude fluctuations, which appears due to engulfment of small-scale structure by larger structures, and a negative skewness of the distribution of fluctuations, which is the result of spatial dominance of rarefied regions. These features endure even when combining the light curves from independent wind sectors.Conclusions. The stochastic photometric variability of OB stars bears certain signatures of the line-driven wind instability. The distribution function of observed photometric data shows negative skewness and the power spectra of a fraction of light curves exhibit a knee. This can be explained as a result of the line-driven wind instability triggered by stochastic base perturbations.

Klasifikace

  • Druh

    J<sub>imp</sub> - Článek v periodiku v databázi Web of Science

  • CEP obor

  • OECD FORD obor

    10308 - Astronomy (including astrophysics,space science)

Návaznosti výsledku

  • Projekt

    <a href="/cs/project/GA18-05665S" target="_blank" >GA18-05665S: Ztráta hmoty v pozdních fázích vývoje hmotných hvězd</a><br>

  • Návaznosti

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

Ostatní

  • Rok uplatnění

    2021

  • Kód důvěrnosti údajů

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

Údaje specifické pro druh výsledku

  • Název periodika

    Astronomy and Astrophysics

  • ISSN

    0004-6361

  • e-ISSN

  • Svazek periodika

    648

  • Číslo periodika v rámci svazku

    April

  • Stát vydavatele periodika

    FR - Francouzská republika

  • Počet stran výsledku

    9

  • Strana od-do

    „A79“

  • Kód UT WoS článku

    000647070100001

  • EID výsledku v databázi Scopus

    2-s2.0-85104233564