ИСТИНА

We report the detection of a new hard X-ray outbursts of the transient X-ray binary pulsar GS1843+009 with IBIS/ISGRI detector aboard INTEGRAL. The source was detected during November 10–22, 2003; May 1–13, 2004, September 2–11, 2004; October 26–Novenber 2, 2004 with mean flux 12, 10, 7 and 7.2 mCrab respectively in the 20–50 keV energy range at a S/N ratio 7, 7, 5, 6 respectively. These source outbursts were much weaker than the four known ones (1988, 1977,May 2003, 2005). We report here the analysis of INTEGRAL observations at different epochs. The long-term behaviour of the source tends to indicate 180-days periodical outbursts in the highmass X-ray binary system with Be companion. We explain the origin of GS1843+009 X-ray outbursts in terms of the model of colliding winds at the periastron. Physical parameters of the model have been evaluated.