[vsnet-grb-info 19148] GRB 170219A: POLAR Observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  20719
SUBJECT: GRB 170219A: POLAR Observation
DATE:    17/02/22 08:18:10 GMT
FROM:    Zhao Yi at POLAR  <yizhao at ihep.ac.cn>

Minzi Feng (IHEP), Yi Zhao (IHEP), Yuanhao Wang (IHEP)
report on behalf of the POLAR collaboration:


At 2017-02-19T00:03:07.00 UT (T0), during a routine on-ground 
search of data, POLAR detected the GRB 170219A, 
which was also detected by the 
Fermi/GBM (trigger 509155392/170219002, Circ 20706),
CALET/GBM (Cherry et al. 2017, GCN 20710)
INTEGRAL/SPIACS (trigger 7701), Konus-Wind
(Frederiks et al. 2017, GCN 20703) and for which a triangulated
position was reported by IPN (Svinkin et al. 2017, GCN 20702).


The POLAR light curve consists of a single peak,
with a duration (T90) of 0.15 s measured from T0+0.08 s.
The 10-ms peak rate measured from T0+0.12 s is 16148.3 cnts/s.
The total counts is about 964 cnts. 


LC_URL:
http://polar.ihep.ac.cn/grb/2017/02/GRB170219A/lc/POLAR_lc_grb170219A.png


The above results are not dead time corrected. The above
measurements are in the energy range of about 20-500 keV.


Using the best location from the Fermi/GBM, which is (J2000):
RA:     72.730     [deg]
Dec:    +49.980    [deg]
Err:    2.88       [deg]


the incident angle in POLAR coordinate at T0 is:
theta:  59.8       [deg]
phi:    -90.2      [deg]


All 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/pub/.