Precise physical parameters of three late-type eclipsing binary giant stars in the Large Magellanic Cloud

Astronomy and Astrophysics, vol. 692, pp. A110

Abstract

Context. Detached eclipsing binaries (DEBs) allow for the possibility of a precise characterization of their stellar components. They offer a unique opportunity for deriving their physical parameters nearly independent of a model for a number of systems consisting of late-type giant stars. We aim to expand the sample of low-metallicity late-type giant stars with precisely determined parameters. Aims. We determine the fundamental parameters, such as the mass and radius, or the effective temperature for three long-period late-type eclipsing binaries from the Large Magellanic Cloud: OGLE-LMC-ECL-25304, OGLE-LMC-ECL-28283, and OGLE-IV LMC554.19.81. Subsequently, we determine the evolutionary stages of the systems. Methods. We fit the light curves from the OGLE project and radial velocity curves from high-resolution spectrographs using the Wilson-Devinney code. The spectral analysis was performed with the GSSP code and resulted in the determination of atmospheric parameters such as effective temperatures and metallicities. We used the isochrones provided by the MIST models based on the MESA code to derive the evolutionary status of the stars. Results. We present the first analysis of three DEBs composed of similar helium-burning late-type stars that pass through the blue loop. The estimated masses for OGLE-LMC-ECL-29293 (G4III + G4III) are M1 = 2.898 ± 0.031 and M2 = 3.153 ± 0.038 M⊙, and the stellar radii are R1 = 19.43 ± 0.31 and R2 = 19.30 ± 0.31 R⊙. OGLE-LMC-ECL-25304 (G4III + G5III) has stellar masses of M1 = 3.267 ± 0.028 and M2 = 3.229 ± 0.029 M⊙ and radii of R1 = 23.62 ± 0.42 and R2 = 25.10 ± 0.43 R⊙. OGLE-IV LMC554.19.81 (G2III + G2III) has masses of M1 = 3.165 ± 0.020 and M2 = 3.184 ± 0.020 M⊙ and radii of R1 = 18.86 ± 0.26 and R2 = 19.64 ± 0.26 R⊙. All masses were determined with a precision better than 2% and the precision for the radii is better than 1.5%. The ages of the stars are in the range of 270–341 Myr.

Authors 18

1. Gonzalo Rojas García

   Nicolaus Copernicus Astronomical Center

   Affiliation as printed

   Nicolaus Copernicus Astronomical Centre , Bartycka 18 , 00-716 Warsaw , Poland

2. D. Graczyk

   Nicolaus Copernicus Astronomical Center

   Affiliation as printed

   Nicolaus Copernicus Astronomical Centre , Rabiańska 8 , 87-100 Toruń , Poland

3. Grzegorz Pietrzyński

   Nicolaus Copernicus Astronomical Center

   Affiliation as printed

   Nicolaus Copernicus Astronomical Centre , Bartycka 18 , 00-716 Warsaw , Poland

4. C. Galan

   Nicolaus Copernicus Astronomical Center

   Affiliation as printed

   Nicolaus Copernicus Astronomical Centre , Bartycka 18 , 00-716 Warsaw , Poland

5. W. Gieren

   University of Concepción

   Affiliation as printed

   Departamento de Astronomía , Universidad de Concepción , Casilla 160-C , Concepción , Chile

6. I. Thompson

   Carnegie Observatories

   Affiliation as printed

   Carnegie Observatories , 813 Santa Barbara Street , Pasadena , CA 91101-1292 , USA

7. K. Suchomska

   Nicolaus Copernicus Astronomical Center

   Affiliation as printed

   Nicolaus Copernicus Astronomical Centre , Bartycka 18 , 00-716 Warsaw , Poland

8. Mikołaj Kałuszyński

   Nicolaus Copernicus Astronomical Center

   Affiliation as printed

   Nicolaus Copernicus Astronomical Centre , Bartycka 18 , 00-716 Warsaw , Poland

9. I. Soszyński

   University of Warsaw

   Affiliation as printed

   Astronomical Observatory , University of Warsaw , Al. Ujazdowskie 4 , 00-478 Warsaw , Poland

10. Andrzej Udalski

    University of Warsaw

    Affiliation as printed

    Astronomical Observatory , University of Warsaw , Al. Ujazdowskie 4 , 00-478 Warsaw , Poland

11. P. Karczmarek

    University of Concepción

    Affiliation as printed

    Departamento de Astronomía , Universidad de Concepción , Casilla 160-C , Concepción , Chile

12. W. Narloch

    Nicolaus Copernicus Astronomical Center

    Affiliation as printed

    Nicolaus Copernicus Astronomical Centre , Bartycka 18 , 00-716 Warsaw , Poland

13. Marek Górski

    Nicolaus Copernicus Astronomical Center

    Affiliation as printed

    Nicolaus Copernicus Astronomical Centre , Bartycka 18 , 00-716 Warsaw , Poland

14. Piotr Wielgórski

    Nicolaus Copernicus Astronomical Center

    Affiliation as printed

    Nicolaus Copernicus Astronomical Centre , Bartycka 18 , 00-716 Warsaw , Poland

15. Bartłomiej Zgirski

    University of Concepción

    Affiliation as printed

    Departamento de Astronomía , Universidad de Concepción , Casilla 160-C , Concepción , Chile

16. G. Hajdu

    Nicolaus Copernicus Astronomical Center

    Affiliation as printed

    Nicolaus Copernicus Astronomical Centre , Bartycka 18 , 00-716 Warsaw , Poland

17. B. Pilecki

    Nicolaus Copernicus Astronomical Center

    Affiliation as printed

    Nicolaus Copernicus Astronomical Centre , Bartycka 18 , 00-716 Warsaw , Poland

18. Mónica Taormina

    Nicolaus Copernicus Astronomical Center

    Affiliation as printed

    Nicolaus Copernicus Astronomical Centre , Bartycka 18 , 00-716 Warsaw , Poland