////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  8395
SUBJECT: GRB 081022: Swift detection of a burst
DATE:    08/10/22 14:39:25 GMT
FROM:    Jamie A. Kennea at PSU/Swift-XRT  <kennea@astro.psu.edu>

G. Stratta (ASDC), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), P. A. Evans (U Leicester),
N. Gehrels (NASA/GSFC), C. Guidorzi (INAF-OAB),
S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU),
J. A. Kennea (PSU), J. Mao (INAF-OAB),
C. B. Markwardt (CRESST/GSFC/UMD), P. T. O'Brien (U Leicester),
J. P. Osborne (U Leicester), K. L. Page (U Leicester),
M. Perri (ASDC), B. Preger (ASDC), P. Romano (INAF-IASFPA),
B. Sbarufatti (INAF-IASFPA), M. Stamatikos (NASA/ORAU),
L. Vetere (PSU) and H. Ziaeepour (UCL-MSSL) report on behalf of the
Swift Team:

At 14:23:48 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 081022 (trigger=332399). 
The BAT on-board calculated location is 
RA, Dec 226.619, +12.416 which is 
   RA(J2000) = 15h 06m 28s
   Dec(J2000) = +12d 24' 58"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  This was an image trigger in BAT, but the 
light curve shows a long, smooth, 100 second wide peak with a maximum 
of ~500 cts/sec at T+50 seconds. 

Due to an observing constraint, Swift cannot slew to the BAT position. 
There will thus be no XRT or UVOT data for this trigger. 

Burst Advocate for this burst is G. Stratta (giulia.stratta AT asdc.asi.it). 
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.)

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  8397
SUBJECT: GRB 081022, Swift-BAT refined analysis
DATE:    08/10/22 20:41:45 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

T. N. Ukwatta (GWU) S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
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),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU),
G. Stratta (ASDC), J. Tueller (GSFC)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+903 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 081022 (trigger #332399)
(Stratta, et al., GCN Circ. 8395).  The BAT ground-calculated position is
RA, Dec = 226.584, 12.409 deg which is 
   RA(J2000)  =  15h 06m 20.1s 
   Dec(J2000) = +12d 24' 32.7" 
with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 64%.
 
The mask-weighted light curve shows a long smooth peak starting at ~T-10 sec,
peaking around T+50 sec, and ending around T+210 sec.
T90 (15-350 keV) is 160 +- 40 sec (estimated error including systematics).
 
The time-averaged spectrum from T-9.3 to T+207.3 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.67 +- 0.11.  The fluence in the 15-150 keV band is 2.5 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+57.18 sec in the 15-150 keV band
is 0.6 +- 0.1 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/332399/BA/