Mass-ratio distribution of contact binary stars

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F23%3A10467330" target="_blank" >RIV/00216208:11320/23:10467330 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=1.bIwjIzo6" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=1.bIwjIzo6</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/202245613" target="_blank" >10.1051/0004-6361/202245613</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Mass-ratio distribution of contact binary stars

Popis výsledku v původním jazyce

The mass ratio q of a contact binary star evolves through mass transfer, magnetic braking, and thermal relaxation oscillations to low values until it crosses a critical threshold q(min). When this occurs, the binary undergoes the tidal Darwin instability, leading to a rapid coalescence of the components and to an observable brightening of the system. The distribution of q has not been measured on a sufficiently large population of contact binary stars so far because determining q for a single contact binary usually requires spectroscopy. As was shown previously, however, it is possible to infer the mass-ratio distribution of the entire population of contact binaries from the observed distribution of their light-curve amplitudes. Employing Bayesian inference, we obtained a sample of contact binary candidates from the Kepler Eclipsing Binary Catalog combined with data from Gaia and estimates of effective temperatures. We assigned a probability of being a contact binary of either late or early type to each candidate. Overall, our sample includes about 300 late-type and 200 early-type contact binary candidates. We modeled the amplitude distribution assuming that mass ratios are described by a power law with an exponent b and a cutoff at q(min). We find q(min) = 0.087(-0.015)(+0.024) for late-type contact binaries with periods longer than 0.3 days. For late-type binaries with shorter periods, we find q(min) = 0.246(-0.046)(+0.029) , but the sample is small. For early-type contact binary stars with periods shorter than one day, we obtain q(min) = 0.030(-0.022)(+0.018) . These results indicate a dependence of q(min) on the structure of the components, and they are broadly compatible with previous theoretical predictions. We do not find any clear trends in b. Our method can easily be extended to large samples of contact binaries from TESS and other space-based surveys.

Název v anglickém jazyce

Mass-ratio distribution of contact binary stars

Popis výsledku anglicky

The mass ratio q of a contact binary star evolves through mass transfer, magnetic braking, and thermal relaxation oscillations to low values until it crosses a critical threshold q(min). When this occurs, the binary undergoes the tidal Darwin instability, leading to a rapid coalescence of the components and to an observable brightening of the system. The distribution of q has not been measured on a sufficiently large population of contact binary stars so far because determining q for a single contact binary usually requires spectroscopy. As was shown previously, however, it is possible to infer the mass-ratio distribution of the entire population of contact binaries from the observed distribution of their light-curve amplitudes. Employing Bayesian inference, we obtained a sample of contact binary candidates from the Kepler Eclipsing Binary Catalog combined with data from Gaia and estimates of effective temperatures. We assigned a probability of being a contact binary of either late or early type to each candidate. Overall, our sample includes about 300 late-type and 200 early-type contact binary candidates. We modeled the amplitude distribution assuming that mass ratios are described by a power law with an exponent b and a cutoff at q(min). We find q(min) = 0.087(-0.015)(+0.024) for late-type contact binaries with periods longer than 0.3 days. For late-type binaries with shorter periods, we find q(min) = 0.246(-0.046)(+0.029) , but the sample is small. For early-type contact binary stars with periods shorter than one day, we obtain q(min) = 0.030(-0.022)(+0.018) . These results indicate a dependence of q(min) on the structure of the components, and they are broadly compatible with previous theoretical predictions. We do not find any clear trends in b. Our method can easily be extended to large samples of contact binaries from TESS and other space-based surveys.

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/LTAUSA18093" target="_blank" >LTAUSA18093: Časová proměnnost v astronomii: účast v projektu All-Sky Automated Survey for Supernovae</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2023

Kód důvěrnosti údajů

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

Název periodika

Astronomy &amp; Astrophysics

ISSN

0004-6361

e-ISSN

1432-0746

Svazek periodika

672

Číslo periodika v rámci svazku

April

Stát vydavatele periodika

FR - Francouzská republika

Počet stran výsledku

27

Strana od-do

A176

Kód UT WoS článku

000974975600010

EID výsledku v databázi Scopus

2-s2.0-85156274476