GX 17+2

M. Oda and the Hakucho Team report: "Hakucho has observed three x-ray bursts from a position consistent with that of the galactic bulge x-ray source GX 17+2 = 4U 1813-14 (which has not been previously known to exhibit burst activity). The times, peak fluxes (1-30 keV), durations and error-circle diameters for the three bursts are as follows: 1981 UT Peak flux Duration Error May 21d05h49m 1.8 Crab ~ 0.5 min 0o.5 25 00 08 0.3 Crab ~ 0.5 min 0o.1 25 12 38 0.6 Crab ~ 1.0 min 0o.5 The persistent flux from GX 17+2 at the time of the burst was 0.6 Crab (1-30 keV). Optical observations of the suggested optical counterpart (cf. IAUC 3620) would be useful." S. Kahn, J. Grindlay, J. Halpern and E. Ladd, Center for Astrophysics, report: "We have independently discovered an x-ray burst from the vicinity of GX 17+2 with the Monitor Proportional Counter on the Einstein Observatory. The burst took place on 1980 Mar. 29d 01h45m UT. It was a considerably weaker event than the Hakucho bursts, with a peak flux of ~ 0.15 Crab in the 2-6-keV band, and it had a much shorter decay time, ~ 7.5 s. The risetime of the burst was ~ 2 s. A spectrum obtained at the burst maximum yielded a best fit blackbody temperature > 1.3 keV (90-percent confidence). The burst was not observed simultaneously by the Einstein High Resolution Imager, which is sensitive to lower-energy x-rays. This implies that the absorbing column density to the burst source must be > 2.4 x 10**26 m**-2, consistent with the value obtained for the steady source GX 17+2. The persistent flux from GX 17+2 was 0.56 Crab (2-6 keV) at the time of the burst."