Refinement of third body parameters and new photometric results for the early-type multiple system IU Aurigae


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OZDEMIR S., MAYER P., DRECHSEL H., DEMIRCAN O., Ak H.

ASTRONOMY & ASTROPHYSICS, vol.403, no.2, pp.675-681, 2003 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 403 Issue: 2
  • Publication Date: 2003
  • Doi Number: 10.1051/0004-6361:20030392
  • Title of Journal : ASTRONOMY & ASTROPHYSICS
  • Page Numbers: pp.675-681

Abstract

The massive eclipsing binary system IU Aurigae is re-analyzed in the context of new photometric observations and an improved treatment of its long-term period changes (O-C diagram) derived from new times of minima. The best-fit of the O-C curve reveals that the third component is orbiting around the system with a period of 293.3 days in a highly eccentric orbit (e = 0.62). A solution of the most recent UBV light curves obtained during 1997/1998 showed a third light contribution of approximate to23% and continuation of the orbital plane precession of IU Aurigae. Since the revised mass of the third component deduced from the analysis of the O-C curve of m(3) = 14.2 M-. would imply a larger fraction of third light than suggested by the value of 23% derived from the light curve analysis, the third body is possibly composed of two components. A q-search test applied to the UBV light curves yields a minimum chi(2) value at q = 0.67 +/- 0.02, which confirms previous photometric and spectroscopic solutions.