The pulsation properties of lambda bootis stars I. the southern TESS sample

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F20%3A00116124" target="_blank" >RIV/00216224:14310/20:00116124 - isvavai.cz</a>

Výsledek na webu

<a href="https://academic.oup.com/mnras/article-abstract/495/2/1888/5834555" target="_blank" >https://academic.oup.com/mnras/article-abstract/495/2/1888/5834555</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1093/mnras/staa1271" target="_blank" >10.1093/mnras/staa1271</a>

Jazyk výsledku

angličtina

Název v původním jazyce

The pulsation properties of lambda bootis stars I. the southern TESS sample

Popis výsledku v původním jazyce

We analyse TESS light curves for 70 southern lambda Boo stars to identify binaries and to determine which of them pulsate as delta Scuti stars. We find two heartbeat stars and two eclipsing binaries among the sample. We calculate that 81 per cent of lambda Boo stars pulsate as delta Sct variables, which is about twice that of normal stars over the same parameter space. We determine the temperatures and luminosities of the lambda Boo stars from photometry and Gaia DR2 parallaxes. A subset of 40 lambda Boo stars have 2-min TESS data, reliable temperatures and luminosities, and delta Sct pulsation. We use Petersen diagrams (period ratios), echelle diagrams, and the periodluminosity relation to identify the fundamental mode in 20 of those 40 stars and conclude that a further 8 stars are not pulsating in this mode. For the remaining 12, the fundamental mode cannot be unambiguously identified. Further mode identification is possible for 12 of the fundamental mode pulsators that have regular sequences of pulsation overtones in their echelle diagrams. We use stellar evolutionmodels to determine statistically that the lambda Boo stars are only superficially metal weak. Simple pulsation models also better fit the observations at a metallicity of Z = 0.01 than at Z = 0.001. The TESS observations reveal the great potential of asteroseismology on lambda Boo stars, for determining precise stellar ages and shedding light on the origin(s) of the lambda Boo phenomenon.

Název v anglickém jazyce

The pulsation properties of lambda bootis stars I. the southern TESS sample

Popis výsledku anglicky

We analyse TESS light curves for 70 southern lambda Boo stars to identify binaries and to determine which of them pulsate as delta Scuti stars. We find two heartbeat stars and two eclipsing binaries among the sample. We calculate that 81 per cent of lambda Boo stars pulsate as delta Sct variables, which is about twice that of normal stars over the same parameter space. We determine the temperatures and luminosities of the lambda Boo stars from photometry and Gaia DR2 parallaxes. A subset of 40 lambda Boo stars have 2-min TESS data, reliable temperatures and luminosities, and delta Sct pulsation. We use Petersen diagrams (period ratios), echelle diagrams, and the periodluminosity relation to identify the fundamental mode in 20 of those 40 stars and conclude that a further 8 stars are not pulsating in this mode. For the remaining 12, the fundamental mode cannot be unambiguously identified. Further mode identification is possible for 12 of the fundamental mode pulsators that have regular sequences of pulsation overtones in their echelle diagrams. We use stellar evolutionmodels to determine statistically that the lambda Boo stars are only superficially metal weak. Simple pulsation models also better fit the observations at a metallicity of Z = 0.01 than at Z = 0.001. The TESS observations reveal the great potential of asteroseismology on lambda Boo stars, for determining precise stellar ages and shedding light on the origin(s) of the lambda Boo phenomenon.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2020

Kód důvěrnosti údajů

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

Název periodika

Monthly Notices of the Royal Astronomical Society

ISSN

0035-8711

e-ISSN

1365-2966

Svazek periodika

495

Číslo periodika v rámci svazku

2

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

25

Strana od-do

1888-1912

Kód UT WoS článku

000543015800025

EID výsledku v databázi Scopus

2-s2.0-85095536018