Variable Blue Straggler Stars in the Open Cluster NGC 6819 Observed in the Kepler “Superstamp” Field

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F23%3A00571209" target="_blank" >RIV/67985815:_____/23:00571209 - isvavai.cz</a>

Výsledek na webu

<a href="https://hdl.handle.net/11104/0342483" target="_blank" >https://hdl.handle.net/11104/0342483</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/1538-3881/acc0f0" target="_blank" >10.3847/1538-3881/acc0f0</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Variable Blue Straggler Stars in the Open Cluster NGC 6819 Observed in the Kepler “Superstamp” Field

Popis výsledku v původním jazyce

We present light curves and pulsation frequency analyses derived from custom photometric reductions for five confirmed cluster members-four blue stragglers and one star near the main-sequence turnoff. Two of these stars show a rich spectrum of delta Scuti pulsation modes, with 236 and 124 significant frequencies identified, respectively, while two stars show mainly low-frequency modes, characteristic of gamma Doradus variable stars. The fifth star, a known active X-ray binary, shows only several harmonics of two main frequencies. For the two delta Scuti stars, we use a frequency separation-mean density relation to estimate their mean densities, and then use these values along with their effective temperature to derive their stellar masses and radii. For the two stars showing low frequencies, we searched for period-spacing sequences that may be representative of gravity-mode or Rossby-mode sequences, but found no clear sequences. The common age for the cluster members, considered along with the frequencies, will provide valuable constraints for asteroseismic analyses, and may shed light on the origin of the blue stragglers.

Název v anglickém jazyce

Variable Blue Straggler Stars in the Open Cluster NGC 6819 Observed in the Kepler “Superstamp” Field

Popis výsledku anglicky

We present light curves and pulsation frequency analyses derived from custom photometric reductions for five confirmed cluster members-four blue stragglers and one star near the main-sequence turnoff. Two of these stars show a rich spectrum of delta Scuti pulsation modes, with 236 and 124 significant frequencies identified, respectively, while two stars show mainly low-frequency modes, characteristic of gamma Doradus variable stars. The fifth star, a known active X-ray binary, shows only several harmonics of two main frequencies. For the two delta Scuti stars, we use a frequency separation-mean density relation to estimate their mean densities, and then use these values along with their effective temperature to derive their stellar masses and radii. For the two stars showing low frequencies, we searched for period-spacing sequences that may be representative of gravity-mode or Rossby-mode sequences, but found no clear sequences. The common age for the cluster members, considered along with the frequencies, will provide valuable constraints for asteroseismic analyses, and may shed light on the origin of the blue stragglers.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

<a href="/cs/project/GA22-34467S" target="_blank" >GA22-34467S: Interakce dvojhvězd na větvi červených obrů: horcí podtrpaslíci jako testovací případ.</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2023

Kód důvěrnosti údajů

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

Název periodika

Astronomical Journal

ISSN

0004-6256

e-ISSN

1538-3881

Svazek periodika

165

Číslo periodika v rámci svazku

5

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

15

Strana od-do

188

Kód UT WoS článku

000962627400001

EID výsledku v databázi Scopus

2-s2.0-85151724834