Resumen

KOENIGSBERGER, G.. On the nature of the LBV/WR eclipsing binary system HD 5980. Rev. mex. astron. astrofis [online]. 2004, vol.40, n.2, pp.107-135. ISSN 0185-1101.

HD 5980 is a multiple star system in the Small Magellanic Cloud that underwent a luminous blue variable-like eruption in 1993-1994. The erupting star (star A) forms part of a close eclipsing binary whose companion's (star B) Wolf-Rayet nature has recently been questioned. The data analyzed in this paper cover the period 1979-2002, and support the WNE classification of star B. The orbital phase-dependent variations of ultraviolet P Cygni absorption lines imply that the wind speed of star A is 1700-2200 km s^-1 and that of star B is 2600-3100 km s^-1. These allow an estimate of the wind-wind collision (WWC) shock cone geometry and line profiles from the WWC region. Given the assumed mass-loss rates, only a small fraction of the observed emission line profiles may originate in the WWC region. The star A+starB binary pair is likely the result of evolution with mass transfer and/or evolution with rapid rotation, and provides a magnificent opportunity for studying the processes that occur in massive multiple systems at the stages of stellar evolution just prior to the supernova event.

Palabras llave : Stars [Binaries (Eclipsing)]; Stars [Individual (HD 5980)]; Stars [Winds]; Stars [Outflows]; Stars [Wolf-Rayet]; Stars [Variables (Luminous Blue Variables)].

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