[vsnet-grb-info 18880] GRB 161219B: POLAR Observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  20331
SUBJECT: GRB 161219B: POLAR Observation 
DATE:    16/12/22 10:38:13 GMT
FROM:    Haulin Xiao at PSI/POLAR  <hualin.xiao at psi.ch>

Hualin Xiao (PSI), Wojtek Hajdas (PSI) and Radek Marcinkowski (PSI) report on behalf of the POLAR collaboration:

At 2016-12-19T18:48:39.0 UT(T0), during a routine on-ground search of data, POLAR detected the GRB 161219B,
which was also observed by Swift BAT (trigger #727541).

The POLAR light curve consists of one peak with duration (T90) of 4.0 +- 0.5 s measured from T0.
The  0.5 s peak flux at T0+1.75 s  is equal to 248 +-44 cnts/sec.
Above measurements are in the energy range of about 80 - 500 keV.

LC_URL: http://polar.psi.ch/triggers/GRB161219B.png
 and http://polar.psi.ch/pub/lc.php?event=GRB+161219B

Using the best location from the Swift BAT, which is (J2000):

RA: 91.717  [deg]
	
Dec: -26.790  [deg]

the incident angle in the POLAR coordinate at T0 is:

Theta: 96.6  [deg]

Phi:  201.2 [deg]

The analysis results presented above are preliminary. Calibration of the instrument is ongoing.

POLAR is a dedicated Gamma-Ray Burst polarimeter which was launched on-board the Chinese space
laboratory Tiangong-2 (TG-2) on Sep 15, 2016. The energy detection range of POLAR is ~ 50-500 keV.
More information about POLAR can be found at http://polar.psi.ch/pub , http://polar.ihep.ac.cn/en/ and http://isdc.unige.ch/polar/ .


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