Yazar "van Heerden, H. P." seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • [ X ]
    Öğe
    Absolute parameters of detached binaries in the southern sky - III: HO Tel
    (Elsevier Science Bv, 2017) Surgit, D.; Erdem, A.; Engelbrecht, C. A.; van Heerden, H. P.; Manick, R.
    We present the first radial velocity analysis of the southern eclipsing binary star HO Tel, based on spectra obtained at the South African Astronomical Observatory in 2013. The orbital solution of this neglected binary gave the quite large spectroscopic mass ratio of 0.921(+/- 0.005). The V light curve from the All Sky Automated Survey (ASAS) and Walraven five-colour (WULBV) photometric light curves (Spoelstra and Van Houten 1972) were solved simultaneously using the Wilson-Devinney code supplemented by the Monte Carlo search method. The final photometric model describes HO Tel as a detached binary star where both component stars fill about three-quarters of their Roche limiting lobes. The masses and radii were found to be 1.88(+/- 0.04) M-circle dot, 2.28(+/- 0.15) R-circle dot and 1.73(+/- 0.04) M-circle dot, 2.08(+/- 0.16) R-circle dot for the primary and secondary components of the system, respectively. The distance to HO Tel was calculated as 282(+/- 30) pc, taking into account interstellar extinction. The evolution case of HO Tel was also examined. Both components of the system are evolved main-sequence stars with an age of approximately 1.1 Gy, when compared to Geneva theoretical evolution models. (C) 2017 Elsevier B.V. All rights reserved.
  • [ X ]
    Öğe
    Absolute parameters of eclipsing binaries in Southern Hemisphere sky - II: QY Tel
    (Elsevier Science Bv, 2016) Erdem, A.; Surgit, D.; Engelbrecht, C. A.; van Heerden, H. P.; Manick, R.
    This paper presents the first analysis of spectroscopic and photometric observations of the neglected southern eclipsing binary star, QY Tel. Spectroscopic observations were carried out at the South African Astronomical Observatory in 2013. New radial velocity curves from this study and V light curves from the All Sky Automated Survey were solved simultaneously using modern light and radial velocity curve synthesis methods. The final model describes QY Tel as a detached binary star where both component stars fill at least half of their Roche limiting lobes. The masses and radii were found to be 1.32 (+/- 0.06) M-circle dot, 1.74 (+/- 0.15) R-circle dot and 1.44 (+/- 0.09) M-circle dot, 2.70 (+/- 0.16) R-circle dot for the primary and secondary components of the system, respectively. The distance to QY Tel was calculated as 365 (+/- 40) pc, taking into account interstellar extinction. The evolution case of QY Tel is also examined. Both components of the system are evolved main-sequence stars with an age of approximately 3.2 Gy, when compared to Geneva theoretical evolution models. (C) 2016 Elsevier B.V. All rights reserved.