Discovery of X-ray bursts from GX 3+1 /4U 1744-26/

Abstract

During the Hakucho observations of the galactic center region in 1980 July-August, 15 X-ray bursts were observed for the first time from a bright bulge source GX 3+1 (4U 1744-26). These bursts exhibit characteristics typical of type 1 cosmic X-ray bursts. No bursts, however, were observed from GX 3+1 in previous Hakucho observations conducted in 1979 and early 1980. The persistent X-ray flux of GX3+1 in 1979-1980 was roughly half the value obtained in 1971-1978 by other observers.