The double low-mass white dwarf eclipsing binary system J2102-4145 and its possible evolution

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F24%3A00586941" target="_blank" >RIV/67985815:_____/24:00586941 - isvavai.cz</a>

Result on the web

<a href="https://hdl.handle.net/11104/0354889" target="_blank" >https://hdl.handle.net/11104/0354889</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/202348564" target="_blank" >10.1051/0004-6361/202348564</a>

Result language

angličtina

Original language name

The double low-mass white dwarf eclipsing binary system J2102-4145 and its possible evolution

Original language description

In recent years, about 150 low-mass white dwarfs (WDs), typically with masses below 0.4 M-circle dot, have been discovered. The majority of these low-mass WDs are observed in binary systems as they cannot be formed through single-star evolution within Hubble time. In this work, we present a comprehensive analysis of the double low-mass WD eclipsing binary system J2102 4145. Our investigation encompasses an extensive observational campaign, resulting in the acquisition of approximately 28 h of high-speed photometric data across multiple nights using NTT /ULTRACAM, SOAR /Goodman, and SMARTS-1m telescopes. These observations have provided critical insights into the orbital characteristics of this system, including parameters such as inclination and orbital period. To disentangle the binary components of J2102 4145, we employed the XTgrid spectral fitting method with GMOS /Gemini-South and X-shooter data. Additionally, we used the PHOEBE package for light curve analysis on NTT/ULTRACAM high-speed time-series photometry data to constrain the binary star properties. Our analysis unveils remarkable similarities between the two components of this binary system. For the primary star, we determine T-eff,T-1 = 13 688(-72)(+65) K, log g(1) = 7.36 +/- 0.01, R-1 = 0.0211 +/- 0.0002 R-circle dot, and M-1 = 0.375 +/- 0.003 M-circle dot, while, the secondary star is characterised by T-eff,T-2 = 12 952 +/- 53 66 K, log g(2) = 7.32 +/- 0.01, R-2 = 0.0203 +/- 0.0002 0.0003 R-circle dot, and M-2 = 0.314 +/- 0.003 M-circle dot. Furthermore, we found a notable discrepancy between T-eff and R of the less massive WD, compared to evolutionary sequences for WDs from the literature, which has significant implications for our understanding of WD evolution. We discuss a potential formation scenario for this system which might explain this discrepancy and explore its future evolution. We predict that this system will merge in similar to 800 Myr, evolving into a helium-rich hot subdwarf star and later into a hybrid He/CO WD.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

<a href="/en/project/GA22-34467S" target="_blank" >GA22-34467S: Binary interaction on the red giant branch: Hot subdwarfs as a test case.</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2024

Confidentiality

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

Name of the periodical

Astronomy & Astrophysics

ISSN

0004-6361

e-ISSN

1432-0746

Volume of the periodical

685

Issue of the periodical within the volume

May

Country of publishing house

FR - FRANCE

Number of pages

17

Pages from-to

A9

UT code for WoS article

001231008100026

EID of the result in the Scopus database

2-s2.0-85192486993