TITLE:   GCN CIRCULAR
NUMBER:  20277
SUBJECT: GRB 161207A: POLAR observation
DATE:    16/12/17 04:32:48 GMT
FROM:    Yuanhao Wang at IHEP/CAS  <wangyuanhao@ihep.ac.cn>

Y. H. Wang (IHEP), Y. Zhao (IHEP), M. Z. Feng(IHEP), J. C. Sun (IHEP),
Z. H. Li (IHEP), H. C. Li (IHEP), S. L. Xiong (IHEP),T. Batsch(NCBJ),
T. Bernasconi (ISDC/UniGe),F. Cadoux (DPNC/UniGe), Y. W. Dong (IHEP),
M. Y. Ge (IHEP), W.Hajdas (PSI),Y. Huang (IHEP),Karol Jedrzejczak
(NCBJ), M. R. Kole (DPNC/UniGe), F. J. Lu (IHEP), R. Marcinkowski(PSI),
M. Pohl (DPNC/UniGe),N. Produit (ISDC/UniGe),A. Rutczynska (NCBJ),
D. Rybka (NCBJ),L. M. Song (IHEP),J. Szabelski (NCBJ), X. Wen (IHEP),
B. B. Wu (IHEP),X. Wu(DPNC/UniGe), H. L. Xiao (PSI), M. Xu (IHEP),
J. Zhang(IHEP),L. Y. Zhang (IHEP), P. Zhang (PSI), S. N. Zhang(IHEP),
Y. J. Zhang (IHEP), A. Zwolinska (NCBJ)
report for the POLAR collaboration:

At 2016-12-07T20:42:55 UT (T0), during a routine on-ground 
search of data, POLAR detected the GRB 161207A, 
which was also detected by the CALET (GCN Circ #20246) and Fermi/GBM
(trigger 502836132/161207863).

The POLAR light curve consists of several peaks,
with a duration (T90) of 27.4 s measured from T0-2.87 s .
The 1s peak rate measured from T0+19.00 s is 350.4 cnts/s,
The total counts is about 4946 cnts.  The above measurements are
in the energy range of about 80-500 keV.

LC_URL:

http://polar.ihep.ac.cn/grb/2016/GRB161207A/lc/POLAR_lc_grb161207862.jpg

Using the best location from the Fermi/GBM, which is (J2000):
RA:    305.020     [deg]
Dec:   +20.700     [deg]
Err:     4.69      [deg]

the incident angle in POLAR coordinate at T0 is:
theta:  65.4  [deg]
phi:   -28.6  [deg]

The analysis results presented above are preliminary.

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