TITLE: GCN CIRCULAR NUMBER: 12319 SUBJECT: Trigger 502024: Swift detection of KS 1741-293 DATE: 11/09/01 12:44:02 GMT FROM: Scott Barthelmy at NASA/GSFC S. D. Barthelmy (GSFC), S. Campana (INAF-OAB), V. D'Elia (ASDC), N. Gehrels (NASA/GSFC), B. Gendre (ASDC), J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA), C. J. Mountford (U Leicester), D. M. Palmer (LANL), P. Romano (INAF-IASFPA) and B.-B. Zhang (PSU) report on behalf of the Swift Team: At 12:07:22 UT, the Swift Burst Alert Telescope (BAT) triggered and located an outburst from what we tentatively associate with KS 1741-293 (aka M 1741-293 and AX J1744.8-2921) (trigger=502024). Swift did not slew immediately because the on-board merit system gives these sources a low merit value. The BAT on-board calculated location is RA, Dec 266.252, -29.346, which is RA(J2000) = 17h 45m 00s Dec(J2000) = -29d 20' 45" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single weak peak with a duration of about 10 sec. The peak count rate was ~1200 counts/sec (15-350 keV), at ~3 sec after the trigger. The XRT began observing the field at 12:31:49.6 UT, 1467.2 seconds after the BAT trigger. No source was detected in 117 s of promptly downlinked data. We are waiting for the full dataset to detect and localise the XRT counterpart. Although the BAT position is consistent with the LMXRB KS 1741-293, this an extremely crowded field near the Galactic center, so it is possible that the burst came from another Galactic source.