TITLE: GCN CIRCULAR NUMBER: 18675 SUBJECT: Swift detection of 4U 1850-03 DATE: 15/12/09 06:34:43 GMT FROM: Scott Barthelmy at NASA/GSFC S. D. Barthelmy (GSFC), D. M. Palmer (LANL) and B. Sbarufatti (INAF-OAB/PSU) report on behalf of the Swift Team: At 06:08:32 UT, the Swift Burst Alert Telescope (BAT) triggered and located 4U 1850-03 (trigger=666827). Swift did not slew due to observing constraint. The BAT on-board calculated location is RA, Dec 282.088, -2.421, which is RA(J2000) = 18h 48m 21s Dec(J2000) = -02d 25' 16" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). As is typical for image triggers, nothing is visible in the real-time TDRSS light curve. Due to a Sun observing constraint, Swift cannot slew to the BAT position until 10:55 UT on 2016 February 15. There will thus be no XRT or UVOT data for this trigger before this time.