Revisiting the analysis of HW Virginis eclipse timing data: I. A frequentist data modeling approach and a dynamical stability analysis

Creative Commons License

ESMER E. M., BAŞTÜRK Ö., Hinse T. C., SELAM S. O., Correia A. C. M.

ASTRONOMY & ASTROPHYSICS, cilt.648, 2021 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 648
  • Basım Tarihi: 2021
  • Doi Numarası: 10.1051/0004-6361/202038640
  • Dergi Adı: ASTRONOMY & ASTROPHYSICS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Artic & Antarctic Regions, Communication Abstracts, Compendex, INSPEC, Metadex, zbMATH, DIALNET, Civil Engineering Abstracts
  • Anahtar Kelimeler: binaries: eclipsing, stars: individual: HW Vir, planetary systems, subdwarfs, methods: data analysis, ORBITAL PERIOD MODULATION, EXTRA-SOLAR PLANETS, MAGNETIC BRAKING, BINARY, SYSTEM, COMPANIONS, DWARF, CONSTRAINTS, PHOTOMETRY, EVOLUTION
  • Ankara Üniversitesi Adresli: Evet

Özet

Context. HW Vir is a short-period binary that presents eclipse timing variations. Circumbinary planets have been proposed as a possible explanation, although the properties of the planets differ in each new study.Aims. Our aim is to perform robust model selection methods for eclipse timing variations (ETV) and error calculation techniques based on a frequentist approach for the case of the HW Vir system.Methods. We initially performed simultaneous light and radial velocity curve analysis to derive the masses of the binary. We then analyzed the eclipse timing variation of the system by fitting multiple models. To select the best model, we searched the confidence levels for the best model by creating an chi(2) surface grid and bootstrap methods for each pair of parameters. We searched for stable orbital configurations for our adopted ETV model.Results. The masses of the binary are found as 0.413 +/- 0.008 M-circle dot and 0.128 +/- 0.004 M-circle dot. Under the assumption of two light time effects superimposed on a secular change, the minimum masses of the circumbinary objects are calculated as 25.0-2.2+3.5MJup and 13.9(-0.45)(+0.60)M(Jup)13.9-0.45+0.60MJup . The projected semi-major axes are found to be 7.8(-1.0)(+1.4) 7.8-1.0+1.4 and 4.56(-0.22)(+0.27)4.56-0.22+0.27 au in respective order. We find that this configuration is unstable within a 3 sigma range on the semi-major axis and eccentricity of the outer circumbinary object.