Orbital period variation of the eclipsing binary system TT Herculis

SELAM S. O., Albayrak B.

ASTRONOMISCHE NACHRICHTEN, cilt.328, sa.2, ss.154-158, 2007 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 328 Sayı: 2
  • Basım Tarihi: 2007
  • Doi Numarası: 10.1002/asna.200610708
  • Dergi Adı: ASTRONOMISCHE NACHRICHTEN
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.154-158
  • Anahtar Kelimeler: binaries : close, binaries : eclipsing, stars : individual (TT Her), LIGHT-CURVES, LUMINOSITY, ELEMENTS
  • Ankara Üniversitesi Adresli: Evet

Özet

New photoelectric UBV observations were obtained for the eclipsing binary TT Her at the Ankara University Observatory (AUO) and three new times of minima were calculated from these observations. The (O - C) diagram constructed for all available times of minima of TT Her exhibits a cyclic character superimposed on a quadratic variation. The quadratic character yields an orbital period decrease with a rate of dP/dt = -8.83 x 10(-8) day yr(-1) which can be attributed to the mass exchange/loss mechanism in the system. By assuming the presence of a gravitationally bound third body in the system, the analysis of the cyclic nature in the (O - C) diagram revealed a third body with a mass of 0.21 M-circle dot orbiting around the eclipsing pair. The possibility of magnetic activity cycle effect as a cause for the observed cyclic variation in the (O - C) diagram was also discussed. (c) 2007 WILEY-VCH Verlag GmbH & Co. KGaA. Weinheim.