Место издания:Institute of Chemical Technology Prague, Czech Republic
Первая страница:99
Последняя страница:102
Аннотация:We performed digital reduction of a large set of photographic plates for X-ray binary system V4641 Sgr containing a black hole. 277 plates were taken in the time range between 1960 and 1992. Photographic observations reveal lower level of flaring activity if compared with CCD data after the large 1999 outburst. Only single outburst was confirmed which happened in 1978. If archive photographic data is used along with contemporary CCD observations, the orbital period may be improved, and its value is 2.81728 ±0.00004 day.
