GRB 160824B

R. Hamburg (UAH)
reports on behalf of the Fermi GBM Team:

"At 14:21:12.94 UT on 24 August 2016, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 160824B (trigger 493741276 / 160824598).

The on-ground calculated location, using the GBM trigger
data, is RA = 73, DEC = +68, with an uncertainty
of 1 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which we have characterized as a core-plus-tail model, with 90% of
GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg
systematic error. [Connaughton et al. 2015, ApJS, 216, 32] ).

The angle from the Fermi LAT boresight at the GBM trigger time is 121
degrees.

The GBM light curve consists of a single peak
with a duration (T90) of about 3.6 s (50-300 keV).
The time-averaged spectrum from T0-0.26 to T0+3.07 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.20 +/- 0.06 and
the cutoff energy, parameterized as Epeak, is 649.70 +/- 32.60 keV.

The event fluence (10-1000 keV) in this time interval is
(1.39 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+1.7 s in the 10-1000 keV band
is 11.9 +/- 0.4 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."

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),
W. Ishizaki (ICRR), M. L. Cherry (LSU), S. Ricciarini (U of Florence),
P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The long-duration GRB 160824B (Hamburg et al., GCN Circ. 19856
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 ;
INTEGRAL-SPI/ACS trigger #7538) triggered the CALET Gamma-ray Burst Monitor
(CGBM) at 14:21:12.34 on 24 August 2016.  The burst signal was seen by
all CGBM instruments.  Because of a problem in one of the ground alert processing
script, the GCN notice was not distributed automatically for this event.

The light curve of the SGM shows a single peak starting at T+0.5 sec, peaking at
T+1.5 sec and ending at T+4 sec.  The T90 duration measured by the SGM data
is 2.7 +- 0.1 sec (40-1000 keV).

The light curve is available at

http://cgbm.calet.jp/cgbm_trigger/flight/1156083685/

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

N.L.Dzhioeva, A.M.Amelushkin, V.O.Barinova, A.V.Bogomolov, V.V.Bogomolov, 
A.F.Iyudin, V.V.Kalegaev, M.I.Panasyuk, V.L. Petrov, S.I.Svertilov, 
I.V.Yashin
Physics Department, Skobel`tsyn Institute of Nuclear Physics, Moscow State 
University.

I. Park, J. Lee, S. Jeong
Department of Physics, Sungkyunkwan University, Seobu-ro, Jangangu, Suwonsi, 
Korea

V. Lipunov, E.S. Gorbovskoy,   N.Tyurina, 
P.Balanutsa,  A.Kuznetsov, D.Kuvshinov,
Lomonosov Moscow State University, Sternberg Astronomical Institute

K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk
Irkutsk State University

V.Yurkov, Yu.Sergienko, A.Gabovich
Blagoveschensk Educational State University, Blagoveschensk

Fermi GRB 160824B (Hamburg, GCN 19856
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 ; Yoshida et al., GCN 19873
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 ) was 
observed by Lomonosov on 16/08/24 around Fermi/CALET trigger time.

It was visible by all 3 detectors of BDRG  in energy range up to 1 MeV.
The parameters of GRB are:

Total duration ~3s.
Peak intensity in the range 20-1000 keV  >6 photons/cm2*s in the range 20-1000 keV
Peak intensity  in the range 250-1000 keV >2 photons/cm2*s

The Gamma Ray light curve is available at 
http://master.sai.msu.ru/static/GRB160824B_Lomonosov_BDRG.png


MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Tunka was pointed to the  GRB160824B  (Hamburg et al, GCN 
19856
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 ) 62 sec after notice time and 107 sec after trigger time at 
2016-08-24 14:23:00 UT. On our first (20s exposure)  set we  found 56 
optical transient within FERMI error-box (ra=08 21 12 dec=+46 14 00 
r=3.833300) brighter then 15.83, but first alert   have a too large 
coordinate error and this region  is outside final error box.  We cover 
part of final error box 619 sec after trigger time at 2016-08-24 14:31:32 
UT by 3-th alert message. The 5-sigma upper limit has been about 18 mag on 
120 s exposure image. No OT was found.


MASTER II  robotic telescope located in Blagoveschensk  was starded 
inspect inside  the  GRB160824B  (Hamburg et al, GCN 19856
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 , Yoshida et al, 
GCN 19873
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 ) error box  1165  sec after trigger time at 2016-08-24 14:40:38 
UT.  We cover full 1 sigma + 3 degree systematic error box with  5-sigma 
upper limit  about 18 mag. 
No OT was found.

The cover map is available at 
http://master.sai.msu.ru/static/GRB160824B_MASTER_Cover.png  .

  The message may be cited.

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

Analysis of Astrosat data showed the CZTI detection of GRB160824B (Fermi-GBM detection: R. Hamburg et al., GCN Circ. 19856
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 ).

The source was clearly detected in the 40-200 keV energy range. The light curve shows a single peak at 14:21:13.5 UT, 1.5 seconds after Fermi Trigger at 14:21:12 UT. The peak count rate was 388.49 counts/sec above the background (four quadrants summed together), with a total of 992 counts. The local mean background count rate was 120.0 counts/sec. Using cumulative rates, we measure a T90 of 2.9 secs.

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.