GRB 090712

S. T. Holland (CRESST/USRA/GSFC), N. Gehrels (NASA/GSFC),
K. L. Page (U Leicester), D. M. Palmer (LANL),
A. Rowlinson (U Leicester), M. H. Siegel (PSU) and
T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team:

At 03:51:05 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 090712 (trigger=357072).  Swift could not slew due to 
the Sun constraint. 
The BAT on-board calculated location is 
RA, Dec 70.103, +22.557 which is 
   RA(J2000) = 04h 40m 25s
   Dec(J2000) = +22d 33' 26"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single broad
triangular peak structure with a duration of about 100 sec.  
The peak count rate was ~1000 counts/sec (15-350 keV), 
at ~0 sec after the trigger. 

Because of the constraint, the BAT position is unobservable 
by Swift until 21st July 2009. There will thus be no prompt XRT or UVOT 
data for this trigger. 

Burst Advocate for this burst is S. T. Holland (sholland AT milkyway.gsfc.nasa.gov). 
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.)

S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC), S. T. Holland (CRESST/USRA/GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL),
A. M. Parsons (GSFC), 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-239 to T+355 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 090712 (trigger #357072)
(Holland, et al., GCN Circ. 9659
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 ).  The BAT ground-calculated position is
RA, Dec = 70.097, 22.525 deg, which is 
   RA(J2000)  =  04h 40m 23.2s 
   Dec(J2000) = +22d 31' 29.4" 
with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 67%.
 
The mask-weighted light curve shows a mostly smooth peak starting
at ~T-160 sec, peaking at ~T_zero, and ending at ~T+170 sec.
T90 (15-350 keV) is 145 +- 52 sec (estimated error including systematics).
 
The time-averaged spectrum from T-99.1 to T+157.8 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.33 +- 0.11.  The fluence in the 15-150 keV band is 4.0 +- 0.3 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T-6.10 sec in the 15-150 keV band
is 0.9 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/357072/BA/

A. von Kienlin (MPE) reports on behalf of the Fermi GBM Team: 

"At 03:51:00.34 UT on 12 July 2009, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 090712 (trigger 269063462 / 090712160), 
which was also detected by the SWIFT-BAT (Holland et al. 2008, GCN 9659
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 ,
Barthelmy et al., GCN 9660
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 ). The GBM on-ground location is consistent 
with the Swift position. 

The angle from the Fermi LAT boresight is 33 degrees.

The GBM light curve shows one single pulse with a duration (T90) 
of about 72 s (8-1000 keV). The time-averaged spectrum from 
T0-22.528 s to T0+49.153 s is best fit by a power law function 
with an exponential high energy cutoff.  The power law index 
is -0.68 +/- 0.13 and the cutoff energy, parameterized as Epeak, 
is 505 +/- 101 keV (chi squared 511 for 486 d.o.f.).

The event fluence (8-1000 keV) in this time interval is 
(4.2 +/- 0.3)E-06 erg/cm^2. The 1.024-sec peak photon flux measured 
starting from T0+7.168 s in the 8-1000 keV band 
is 0.63 +/- 0.04 ph/s/cm^2.

The spectral analysis results presented above are preliminary; 
final results will be published in the GBM GRB Catalog."