Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 9384

GRB 090516: Swift-BAT refined analysis
2009-05-17T16:59:56Z (15 years ago)
Scott Barthelmy at NASA/GSFC <>
W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), B. A. Rowlinson (U Leicester),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
Using the data set from T-240 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 090516 (trigger #352190)
(Rowlings, et al., GCN Circ. 9374).  The BAT ground-calculated position is
RA, Dec = 138.246, -11.848 deg, which is 
   RA(J2000)  =  09h 12m 59.1s 
   Dec(J2000) = -11d 50' 51.4" 
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 9%.
The mask-weighted light curve shows several overlapping peaks starting
at ~T-20 sec witht he last peak at ~T+180 sec, and then decaying
to background at ~T+330 sec. The burst went out of the BAT FOV at T+700 sec
when Swift did a pre-programmed slew.
T90 (15-350 keV) is 210 +- 65 sec (estimated error including systematics).
The time-averaged spectrum from T-15.5 to T+288.5 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.84 +- 0.11.  The fluence in the 15-150 keV band is 9.0 +- 0.6 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+7.98 sec in the 15-150 keV band
is 1.6 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
The results of the batgrbproduct analysis are available at

[GCN OPS NOTE(17may09): Per author's request, the TBDs in the first sentence
in the third paragraph were replaced with the actual times.]
Looking for U.S. government information and services? Visit