TITLE: GCN CIRCULAR NUMBER: 14266 SUBJECT: GRB 130306A: Swift detection of a burst DATE: 13/03/07 00:07:17 GMT FROM: Scott Barthelmy at NASA/GSFC M. H. Siegel (PSU), B. N. Barlow (PSU), S. D. Barthelmy (GSFC), N. Gehrels (NASA/GSFC), D. Grupe (PSU), D. Malesani (DARK/NBI), C. B. Markwardt (NASA/GSFC), F. E. Marshall (NASA/GSFC), C. J. Mountford (U Leicester), D. M. Palmer (LANL) and B.-B. Zhang (PSU) report on behalf of the Swift Team: At 23:51:01 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 130306A (trigger=550457). Swift did not slew because of a Moon constraint. The BAT on-board calculated location is RA, Dec 279.478, -11.692 which is RA(J2000) = 18h 37m 55s Dec(J2000) = -11d 41' 29" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT real-time TDRSS light curve shows nothing significant as is typical for image triggers. Due to a Moon observing constraint, Swift cannot slew to the BAT position until 05:58 UT on 2013 March 08. There will thus be no XRT or UVOT data for this trigger before this time. We note that this burst was strongly detected by Fermi GBM in a 4.096 second trigger at T-216 seconds (Trigger 384306448) at a location consistent with the BAT location. Swift was slewing at the time of the Fermi Trigger, detecting the afterglow of the GRB in its first 64 second image trigger after the slew ended. Burst Advocate for this burst is M. H. Siegel (siegel AT swift.psu.edu). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)