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TITLE:   GCN CIRCULAR
NUMBER:  13194
SUBJECT: GRB 120402B: Fermi GBM detection
DATE:    12/04/03 14:30:16 GMT
FROM:    Andrew Collazzi at NASA/MSFC/ORAU  <andrew.collazzi@nasa.gov>

Andrew C. Collazzi (NASA/ORAU)
reports on behalf of the Fermi GBM Team:

"At 16:04:00.76 UT on 02 April 2012, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 120402B (trigger 355075442 / 120402.669).
The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 223.7, Dec = -10.4 (J2000 degrees, equivalent to
J2000 14h 55m, -10° 24'), with a statistical uncertainty of 2.6 degrees
(radius, 1-sigma containment, statistical only; there is additionally
a systematic error which is currently estimated to be 2 to 3 degrees).
The angle from the Fermi LAT boresight is 106 degrees.

The GBM light curve shows a soft, bright, main pulse with some small sustained
emission with a duration (T90) of about 17.5 s (50-300 keV). The time-averaged
spectrum from T0-7.46 to T0+20.192 s is equally well fit by Comptonized Power
Law and a Band function.  

For the CPL function, the best fit parameters are alpha = -1.35 +/- 0.11 and 
Epeak = 37.2 +/- 2.2. The fluence (10-1000 keV) in this time interval
is (3.4 +/- 0.12)E-06 erg/cm^2.

For the Band function, the best fit parameters are alpha = -0.48 +/- 0.37, 
Epeak = 27.5 +/- 2.45, and beta = -2.44 +/- 0.09.  
The fluence (10-1000 keV) in this time interval
is (4.2 +/- 0.22)E-06 erg/cm^2.

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

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TITLE:   GCN CIRCULAR
NUMBER:  13216
SUBJECT: GRB 120402B: MASTER early OT limit
DATE:    12/04/04 16:56:24 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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

E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina, 
N.Shatskiy, P.Balanutsa, D.Zimnukhov, A.Kuznetsov, V.V.Chazov, 
A.Kuznetsov, A.Sankovich
Sternberg Astronomical Institute, Moscow State University

V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov
Blagoveschensk Educational State University, Blagoveschensk

A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik
Kislovodsk Solar Station of the Pulkovo Observatory

V.Krushinski, I.Zalozhnich,  A. Popov
Ural State University, Kourovka

Hugo Levato and Carlos Saffe
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)

Claudio Mallamaci, Carlos Lopez and Federico Podest
Observatorio Astronomico Felix Aguilar (OAFA)


MASTER robotic Very Wide Field Cameras    (MASTER: http://observ.pereplet.ru) 
located in Tunka was pointed to the  FERMI GRB 120402B (Collazzi, 
GCN 13194) 64 sec after GRB time at 2012-04-02 16:05:04.583 UT.
On our first (10s exposure) set we haven`t 
found optical transient  within FERMI error-box (RA = 223.7, Dec = -10.4, 
Rad=9 degrees (3 sigma + 3 deg. of systematic error ) .
The MASTER VWF cameras cover full 1 sigma (+ 3 deg. sys. error) 
error box and ~ 95% 3 sigma  (+ 3 deg. sys. error) error box.
The unfiltered upper limit is 12.0 mag.


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