Skip to main content
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 13762

GRB 120913A: Swift detection of a burst
2012-09-13T20:27:23Z (12 years ago)
Scott Barthelmy at NASA/GSFC <>
E. A. Helder (PSU), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), N. Gehrels (NASA/GSFC),
C. Gronwall (PSU), D. Grupe (PSU), J. A. Kennea (PSU),
H. A. Krimm (CRESST/GSFC/USRA), C. B. Markwardt (NASA/GSFC),
D. M. Palmer (LANL), B. Sbarufatti (INAF-OAB/PSU) and
B.-B. Zhang (PSU) report on behalf of the Swift Team:

At 20:18:21 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 120913A (trigger=533568).  Swift did not slew because
of the Sun observing constraint. 
The BAT on-board calculated location is 
RA, Dec 146.437, +26.977 which is 
   RA(J2000)  =  09h 45m 45s
   Dec(J2000) = +26d 58' 36"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows several peaks
with a total duration of at least 40 sec.  (At T+30s, Swift
executed a pre-planned slew that moved the GRB outside of the BAT FOV)
The peak count rate was ~2600 counts/sec (15-350 keV), at ~23 sec 
after the trigger. 

Due to a Sun observing constraint, Swift cannot slew to the BAT
position until 22:34 UT on 2012 September 27. There will thus be no XRT
or UVOT data for this trigger before this time. 

Burst Advocate for this burst is E. A. Helder (helder AT 
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:
Looking for U.S. government information and services? Visit