GRB 161202A

K. P. Mooley (Hintze Fellow, Oxford), T. D. Staley, R. P. Fender 
(Oxford), G. E. Anderson (Curtin), T. Cantwell (Manchester), D. 
Titterington, S. H. Carey, J. Hickish, Y. C. Perrott, N. Razavi-Ghods, 
P. Scott (Cambridge), K. Grainge, A. Scaife (Manchester)

The AMI Large Array robotically triggered on the Swift alert for GRB 
161202A (Sbarufatti et al., GCN 20227
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 ) as part of the 4pisky program, 
and subsequent follow up observations were obtained up to 10 days 
post-burst. Although the data from the first epoch were lost due to 
technical problems, our observations at 15 GHz on 2016 Dec 03.93 and Dec 
05.77 (UT) do not reveal any radio source at the XRT location (Evans et 
al., GCN 20228
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 ), with 3sigma upper limits of 200 uJy and 121 uJy 
respectively.

We thank the AMI staff for scheduling these observations. The AMI-GRB 
database is a log of all GRB follow up observations with the AMI, and is 
available at http://4pisky.org/ami-grb/.

A.Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, P. Oleynik,
M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline
on behalf of the Konus-Wind team, report:

The long-duration GRB 161202A
(Swift-BAT detection and observation: Sbarufatti et al.,
GCN Circ. 20227
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 , Cummings et al., GCN Circ. 20233
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 ;
Fermi-LAT detection: Vianello & Longo, GCN Circ. 20229
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 )
triggered Konus-Wind at T0=83508.822 s UT (23:11:48.822).

The burst light curve shows a multipeaked structure
started at ~T0-57.1 s with a total duration of ~181.0 s.
The emission is seen up to ~2 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB161202_T83508/

As observed by Konus-Wind, the burst
had a fluence of 2.90(-0.40,+0.73)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+3.920 s,
of 3.03(-0.80,+0.80)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+139.520 s)
is best fit in the 20 keV - 2 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -1.43(-0.25,+0.30)
and Ep = 222(-63,+201) keV (chi2 = 65/62 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high-energy photon index: beta < -1.9
(chi2 = 65/61 dof)

The spectrum near the maximum count rate
(measured from T0+0.256 to T0+8.448 s)
is best fit in the 20 keV - 2 MeV range
by the power law with exponential cutoff model:
with  alpha = -0.67(-0.21,+0.24)
and Ep = 203(-20,+26) keV (chi2 = 76/62 dof).
Fitting by the GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high-energy photon index: beta < -2.5
(chi2 = 76/61 dof)

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.

V. Sharma, V. Bhalerao and D. Bhattacharya (IUCAA), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data showed clear detection of a long duration GRB161202A (Swift detection: B. Sbarufatti et al., GCN Circ. 20227
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 ) 
in the 40-200 keV energy range. The light curve shows a multiple peak structure with main peak at 23:11:50 UT, 62 secs before the Swift BAT 
trigger(consistent with GCN 20233
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 ). The measured peak count rate is 230.75 counts/sec above the background in combined data of four quadrants, 
with a total of 1432.98 counts. The local mean background count rate was 345.25 counts/sec. Using cumulative rates, we measure a T90 of 75.25 
sec.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium
of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated 
the project.

Eleonora Troja (GSFC), Nat Butler (ASU), Alan M. Watson (UNAM),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer
(UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB),
Antonino Cucchiara (UVI), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz
(UCSC), Jos�� A. de Diego (UNAM), Leonid Georgiev (UNAM), Jes��s Gonz��lez
(UNAM), Carlos Rom��n-Z����iga (UNAM), Neil Gehrels (GSFC), Harvey Moseley
(GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD)
report:

We observed the field of GRB 161202A (Sbarufatti, et al., GCN 20227
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 ;
Vianello & Longo, GCN 20229
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 ) with the Reionization and Transients
Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson
Telescope at the Observatorio Astron��mico Nacional on Sierra San Pedro
M��rtir from 2016/12 4.08 to 2016/12 4.31 UTC (26.70 to 32.11 hours after
the BAT trigger), obtaining a total of 3.34 hours exposure in the r and i
bands and 1.45 hours exposure in the Z, Y, J, and H bands.

For a source within the Swift-XRT error circle (Burrows, et al., GCN 20231
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 )
in comparison with the SDSS DR9 and 2MASS catalogs, we obtain the following
upper limits (3-sigma):

   r    > 24.0
   i    > 23.9
   Z    > 23.1
   Y    > 22.8
   J    > 22.4
   H    > 22.0

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

We thank the staff of the Observatorio Astron��mico Nacional in San Pedro
M��rtir.

J. R. Cummings (CPI), S. D. Barthelmy (GSFC),
N. Gehrels (GSFC), H. A. Krimm (NSF/USRA),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU),
B. Sbarufatti (INAF-OAB/PSU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Using the data set from T-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 161202A (trigger #725036)
(Sbarufatti, et al., GCN Circ. 20227
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 ).  The BAT ground-calculated position is
RA, Dec = 356.904, 19.652 deg which is
  RA(J2000)  =  23h 47m 36.9s
  Dec(J2000) = +19d 39' 06.3"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 86%.

The first peaks of the burst occurred before it came into the BAT field of view
at ~T-67 s. The mask-weighted light curve shows more than ten pulses that
last till ~T+80 s.

The time-averaged spectrum from T-63.41 to T+65.79 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.55 +- 0.05.  The fluence in the 15-150 keV band is 8.6 +- 0.3 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+2.11 sec in the 15-150 keV band
is 5.9 +- 0.3 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/725036/BA/

M. H. Siegel (PSU) and B. Sbarufatti (INAF-OAB/PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 161202A
83 s after the BAT trigger (Sbarufatti et al., GCN Circ. 20227
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 ).
No optical afterglow consistent with the XRT position
(Evans et al. GCN Circ. 20228
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 )
is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC            83          232          147         >21.2
white               83         4066          344         >21.5
v                 4277         4477          197         >19.4
b                 3661        11907          862         >20.8
u                  295        10303         1027         >20.5
w1                4688         6144          217         >19.6
w2                4071         4271          197         >19.6

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.09 in the direction of the burst
(Schlegel et al. 1998).

D.N. Burrows (PSU), T.G.R. Roegiers (PSU), S.L. Gibson (U. Leicester),
J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), P. D'Avanzo
(INAF-OAB), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA) and B. Sbarufatti
report on behalf of the Swift-XRT team:

We have analysed 8.5 ks of XRT data for GRB 161202A (Sbarufatti et al.
GCN Circ. 20227
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 ), from 66 s to 52.1 ks after the  BAT trigger. The data
comprise 160 s in Windowed Timing (WT) mode (the first 5 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Evans et
al. (GCN Circ. 20228
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 ).

The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=2.53 (+0.41, -0.24). At T+217 s  the decay
flattens to an alpha of 0.83 (+/-0.09) before breaking again at T+8090
s to a final decay with index alpha=1.44 (+0.35, -0.14).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index	of 1.79 (+0.18, -0.17). The
best-fitting absorption column is  9.4 (+1.9, -1.7) x 10^21 cm^-2, in
excess of the Galactic value of 6.0 x 10^20 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 2.79 (+0.24, -0.23)
and a best-fitting absorption column of 1.39 (+0.22, -0.20) x 10^22
cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 3.7 x 10^-11 (1.7 x 10^-10) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:	     1.39 (+0.22, -0.20) x 10^22 cm^-2
Galactic foreground: 6.0 x 10^20 cm^-2
Excess significance: 11.1 sigma
Photon index:	     2.79 (+0.24, -0.23)

If the light curve continues to decay with a power-law decay index of
1.44, the count rate at T+24 hours will be 7.4 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.7 x
10^-13 (1.3 x 10^-12) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00725036.

This circular is an official product of the Swift-XRT team.

D. Kuroda, K. Yanagisawa, Y. Shimizu, H. Toda (OAO, NAOJ),
S. Nagayama (NAOJ), M. Yoshida (Hiroshima), K. Ohta (Kyoto)
and N. Kawai(Tokyo Tech)
report on behalf of MITSuME and OISTER collaboration:

We observed the field of GRB 161202A (Sbarufatti et al., GCNC 20227)
with the optical three color (g', Rc and Ic) CCD camera attached
to the MITSuME 50cm telescope of Okayama Astrophysical Observatory.

The observation started on 2016-12-03 09:13:55 UT (~10.0 h after
the burst). We did not find any new point source within the
enhanced XRT circle (Evans et al., GCNC 20228) in all the three
bands.

Three sigma upper limits of the OT are listed below.
We used SDSS-DR8 catalog for flux calibration.

#T0+[day]  MID-UT    T-EXP[sec]   g'    Rc     Ic
-----------------------------------------------------
0.53482    12:03:00   11580.0   >20.6  >20.2  >19.8
-----------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]

G.Vianello (Stanford), F.Longo (University and INFN, Trieste)

report on behalf of the Fermi-LAT team:


On December, 02, 2016 Fermi-LAT detected high-energy emission from GRB
161202A, which was also detected by Swift (GCN 20227
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 ).

The best LAT on-ground location is found to be

RA, Dec = 356.95, 19.49 (J2000)

with an error radius of 0.13 deg (90 % containment, statistical error
only), which is fully compatible with the enhanced Swift/XRT position
reported in GCN 20228
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 .

This was outside the field of view of the LAT at the time of the
trigger t0 =  23:12:52.7. The location of the GRB was observed however
between t0 + 1680 s and t0 + 3500 s. During this time interval, the
data from the Fermi-LAT show a significant increase in the event rate
correlated with the trigger with high significance.

5 photons were detected above 100 MeV. The highest-energy photon is a
4 GeV event which is observed 2000 seconds after the GBM trigger.

The Fermi-LAT point of contact for this burst is Giacomo Vianello
(giacomov@stanford.edu).

The Fermi-LAT is a pair conversion telescope designed to cover the
energy band from 20 MeV to greater than 300 GeV. It is the product of
an international collaboration between NASA and DOE in the U.S. and
many scientific institutions across France, Italy, Japan and Sweden.

P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 4140 s of XRT Photon Counting mode data and 6 UVOT
images for GRB 161202A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 356.90269, +19.64648 which is equivalent
to:

RA (J2000): 23h 47m 36.65s
Dec (J2000): +19d 38' 47.3"

with an uncertainty of 1.6 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.

B. Sbarufatti (INAF-OAB/PSU), S. D. Barthelmy (GSFC),
D. N. Burrows (PSU), S. B. Cenko (GSFC), J. R. Cummings (NASA/UMBC),
N. Gehrels (NASA/GSFC), C. Gronwall (PSU), N. P. M. Kuin (UCL-MSSL),
F. E. Marshall (NASA/GSFC) and M. H. Siegel (PSU) report on behalf of
the Swift Team:

At 23:12:52 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 161202A (trigger=725036).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 356.895, +19.640, which is 
   RA(J2000)  =  23h 47m 35s
   Dec(J2000) = +19d 38' 23"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows many peaks
with a total duration of about 70 sec.  The peak count rate
was ~10,000 counts/sec (15-350 keV), at ~7 sec after the trigger. 

The XRT began observing the field at 23:14:06.7 UT, 74.1 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source with an enhanced position: RA, Dec
356.9031, 19.6477 which is equivalent to:
   RA(J2000)  = 23h 47m 36.74s
   Dec(J2000) = +19d 38' 51.7"
with an uncertainty of 2.4 arcseconds (radius, 90% containment). This
location is 39 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (6.00 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 9.9
(+6.04/-4.79) x 10^21 cm^-2 (90% confidence). 

The initial flux in the 2.5 s image was 2.18e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 82 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.09. 

Burst Advocate for this burst is B. Sbarufatti (boris.sbarufatti AT brera.inaf.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.)