TESS observations of pulsating subdwarf B stars: extraordinarily short-period gravity modes in CD-28 degrees 1974

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F20%3A00534623" target="_blank" >RIV/67985815:_____/20:00534623 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1093/mnras/staa661" target="_blank" >https://doi.org/10.1093/mnras/staa661</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1093/mnras/staa661" target="_blank" >10.1093/mnras/staa661</a>

Jazyk výsledku

angličtina

Název v původním jazyce

TESS observations of pulsating subdwarf B stars: extraordinarily short-period gravity modes in CD-28 degrees 1974

Popis výsledku v původním jazyce

Transiting Exoplanet Survey Satellite (TESS) observations show CD-28 degrees 1974 to be a gravity(g)-mode-dominated hybrid pulsating subdwarf B (sdBV) star. It shows 13 secure periods that form an l = 1 asymptotic sequence near the typical period spacing. Extraordinarily, these periods lie between 1500 and 3300 s, whereas typical l = 1 g modes in sdBV stars occur between 3300 and 10 000 s. This indicates a structure somewhat different from typical sdBV stars. CD-28 degrees 1974 has a visually close F/G main-sequence companion 1.33 arcsec away, which may be a physical companion. Gaia proper motions indicate a comoving pair with the same distance. A reanalysis of Ultraviolet and Visual Echelle Spectrograph (UVES) spectra failed to detect any orbital motion and the light curve shows no reflection effect or ellipsoidal variability, making an unseen close companion unlikely. The implication is that CD-28 degrees 1974 has become a hot subdwarf via single star or post-merger evolution.

Název v anglickém jazyce

TESS observations of pulsating subdwarf B stars: extraordinarily short-period gravity modes in CD-28 degrees 1974

Popis výsledku anglicky

Transiting Exoplanet Survey Satellite (TESS) observations show CD-28 degrees 1974 to be a gravity(g)-mode-dominated hybrid pulsating subdwarf B (sdBV) star. It shows 13 secure periods that form an l = 1 asymptotic sequence near the typical period spacing. Extraordinarily, these periods lie between 1500 and 3300 s, whereas typical l = 1 g modes in sdBV stars occur between 3300 and 10 000 s. This indicates a structure somewhat different from typical sdBV stars. CD-28 degrees 1974 has a visually close F/G main-sequence companion 1.33 arcsec away, which may be a physical companion. Gaia proper motions indicate a comoving pair with the same distance. A reanalysis of Ultraviolet and Visual Echelle Spectrograph (UVES) spectra failed to detect any orbital motion and the light curve shows no reflection effect or ellipsoidal variability, making an unseen close companion unlikely. The implication is that CD-28 degrees 1974 has become a hot subdwarf via single star or post-merger evolution.

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/GA18-20083S" target="_blank" >GA18-20083S: Gaia-GALEX přehled horkých podtrpaslíků</a><br>

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

1365-2966

e-ISSN

—

Svazek periodika

493

Číslo periodika v rámci svazku

4

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

8

Strana od-do

5162-5169

Kód UT WoS článku

000539094400042

EID výsledku v databázi Scopus

2-s2.0-85095296386