Filling the gap between synchronized and non-synchronized sdBs in short-period sdBV plus dM binaries with TESS: TIC 137608661, a new system with a well-defined rotational splitting

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F22%3A00555050" target="_blank" >RIV/67985815:_____/22:00555050 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1093/mnras/stac160" target="_blank" >https://doi.org/10.1093/mnras/stac160</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1093/mnras/stac160" target="_blank" >10.1093/mnras/stac160</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Filling the gap between synchronized and non-synchronized sdBs in short-period sdBV plus dM binaries with TESS: TIC 137608661, a new system with a well-defined rotational splitting

Popis výsledku v původním jazyce

TIC 137608661/TYC 4544-2658-1/FBS 0938+788 is a new sdBV+dM reflection-effect binary discovered by the TESS space mission with an orbital period of 7.21 h. In addition to the orbital frequency and its harmonics, the Fourier transform of TIC 137608661 shows many g-mode pulsation frequencies from the subdwarf B (sdB) star. The amplitude spectrum is particularly simple to interpret as we immediately see several rotational triplets of equally spaced frequencies. The central frequencies of these triplets are equally spaced in period with a mean period spacing of 270.12 s, corresponding to consecutive l = 1 modes. From the mean frequency spacing of 1.25 mu Hz we derive a rotation period of 4.6 d in the deep layers of the sdB star, significantly longer than the orbital period. Among the handful of sdB+dM binaries for which the sdB rotation was measured through asteroseismology, TIC 137608661 is the non-synchronized system with both the shortest orbital period and the shortest core rotation period. Only NY Vir has a shorter orbital period but it is synchronized. From a spectroscopic follow-up of TIC 137608661 we measure the radial velocities of the sdB star, determine its atmospheric parameters, and estimate the rotation rate at the surface of the star. This measurement allows us to exclude synchronized rotation also in the outer layers and suggests a differential rotation, with the surface rotating faster than the core, as found in few other similar systems. Furthermore, an analysis of the spectral energy distribution of TIC 137608661, together with a comparison between sdB pulsation properties and asteroseismic models, gives us further elements to constrain the system.

Název v anglickém jazyce

Filling the gap between synchronized and non-synchronized sdBs in short-period sdBV plus dM binaries with TESS: TIC 137608661, a new system with a well-defined rotational splitting

Popis výsledku anglicky

TIC 137608661/TYC 4544-2658-1/FBS 0938+788 is a new sdBV+dM reflection-effect binary discovered by the TESS space mission with an orbital period of 7.21 h. In addition to the orbital frequency and its harmonics, the Fourier transform of TIC 137608661 shows many g-mode pulsation frequencies from the subdwarf B (sdB) star. The amplitude spectrum is particularly simple to interpret as we immediately see several rotational triplets of equally spaced frequencies. The central frequencies of these triplets are equally spaced in period with a mean period spacing of 270.12 s, corresponding to consecutive l = 1 modes. From the mean frequency spacing of 1.25 mu Hz we derive a rotation period of 4.6 d in the deep layers of the sdB star, significantly longer than the orbital period. Among the handful of sdB+dM binaries for which the sdB rotation was measured through asteroseismology, TIC 137608661 is the non-synchronized system with both the shortest orbital period and the shortest core rotation period. Only NY Vir has a shorter orbital period but it is synchronized. From a spectroscopic follow-up of TIC 137608661 we measure the radial velocities of the sdB star, determine its atmospheric parameters, and estimate the rotation rate at the surface of the star. This measurement allows us to exclude synchronized rotation also in the outer layers and suggests a differential rotation, with the surface rotating faster than the core, as found in few other similar systems. Furthermore, an analysis of the spectral energy distribution of TIC 137608661, together with a comparison between sdB pulsation properties and asteroseismic models, gives us further elements to constrain the system.

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

2022

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

511

Číslo periodika v rámci svazku

2

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

17

Strana od-do

2201-2217

Kód UT WoS článku

000754319100010

EID výsledku v databázi Scopus

2-s2.0-85125455984