GRB 170124A

W. Ishizaki (ICRR), A. Yoshida, T. Sakamoto, Y. Kawakubo, M. Moriyama,
Y. Yamada (AGU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA), I. Takahashi (IPMU),
Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U),
M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The long-duration GRB 170124A (Fermi-GBM trigger #506984291; Konus-Wind trigger
time on 20:58:06.428 UT) triggered the CALET Gamma-ray Burst Monitor (CGBM) at
20:58:04.58 on 24 January 2017.  The burst signal was seen by all CGBM instruments.

The light curve of the SGM shows two peaks.  The first peak starts at T0,
peaks at T+8 sec and ends at T+15 sec.  The second peak starts at T+15 sec,
peaks at T+23 sec and ends at T+30 sec.  The T90 duration measured by
the SGM data is 20.9 +- 1.3 sec (40-1000 keV).

The light curve is available at

http://cgbm.calet.jp/cgbm_trigger/flight//1169326441/index.html

The CALET data used in this analysis are provided by the Waseda
CALET Operation Center located at the Waseda University.

Yi Zhao (IHEP), R. Marcinkowski (PSI), Xing Wen (IHEP),
H. Xiao (PSI), Minzi Feng (IHEP) and W. Hajdas (PSI)
report on behalf of the POLAR collaboration:

At 2017-01-24T20:58:06.00 UT (T0), during a routine on-ground 
search of data, POLAR detected the GRB 170124A, 
which was also detected by the 
Fermi/GBM (trigger 506984291/170124873), Konus-Wind and 
the CALET Gamma-ray BurstMonitor (Circ 20556).

The POLAR light curve consists of multiple peaks,
with a duration (T90) of 22.38 s measured from T0+2.26 s.
The 1-s peak rate measured from T0+8.00 s is 514.8 cnts/s.
The total counts is about 7657 cnts. The above measurements
are in the energy range of about 80-500 keV.

LC_URL:
http://polar.ihep.ac.cn/grb/2017/01/GRB170124A/lc/POLAR_lc_grb170124A.png

Using the best location from the Fermi/GBM, which is (J2000):
RA:     282.040  [deg]
Dec:    -75.510  [deg]
Err:    1.00     [deg]

the incident angle in POLAR coordinate at T0 is:
theta:  111.4    [deg]
phi:    -143.2   [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/.