TITLE: GCN CIRCULAR NUMBER: 13068 SUBJECT: Trigger 517876 is a Swift detection of GX 5-1 DATE: 12/03/16 12:28:37 GMT FROM: Scott Barthelmy at NASA/GSFC S. D. Barthelmy (GSFC), V. D'Elia (ASDC), S. T. Holland (STScI), J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA), A. Melandri (INAF-OAB), K. L. Page (U Leicester), D. M. Palmer (LANL), P. Romano (INAF-IASFPA) and B.-B. Zhang (PSU) report on behalf of the Swift Team: At 11:50:40 UT, the Swift Burst Alert Telescope (BAT) triggered and located GX 5-1 (trigger=517876). Swift did not slew to this source because of the Moon observing constraint. The BAT on-board calculated location is RA, Dec 270.260, -25.087, which is RA(J2000) = 18h 01m 02s Dec(J2000) = -25d 05' 13" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). This is 0.6 arcmin from the GX 5-1 location. This was a 13-min image trigger, and as typical the TDRSS lightcurve does not show any activity. Because of the Moon observing constraint, there will be no slew and therefore no XRT or UVOT data on this target. We also note that the on-board identification for this trigger went out on the GCN Notices as SAX_J1819.3-252 which is not correct and it did not find the the GX 5-1 entry, and as such this caused a notice to be issued. The correct identification is the ground identification of GX 5-1, and is believed to be in its normal range of variability.