GRB 140930A

H. Negoro (Nihon U.), S. Ueno, H. Tomida, S. Nakahira, M. Kimura, M. Ishikawa, Y. E. Nakagawa (JAXA), 
T. Mihara, M. Sugizaki, M. Morii, M. Serino, J. Sugimoto, T. Takagi, A. Yoshikawa, M. Matsuoka (RIKEN), 
N. Kawai, T. Yoshii, Y. Tachibana (Tokyo Tech), 
A. Yoshida, T. Sakamoto, Y. Kawakubo, H. Ohtsuki (AGU), 
H. Tsunemi, D. Uchida (Osaka U.), 
M. Nakajima, K. Fukushima, T. Onodera, K. Suzuki, T. Namba, M. Fujita, F. Honda (Nihon U.), 
Y. Ueda, M. Shidatsu, T. Kawamuro, T. Hori (Kyoto U.), 
Y. Tsuboi, A. Kawagoe (Chuo U.), 
M. Yamauchi, Y. Morooka (Miyazaki U.), 
K. Yamaoka (Nagoya U.) ,
report on behalf of the MAXI team:

A bright uncatalogued X-ray transient source was detected with MAXI/GSC 
at UT 2014-09-30T14:26. Assuming that the source flux was constant over 
the transit, we obtain the source position at

(R.A., Dec) = (344.875 deg, 52.428 deg) = (22 59 30, +52 25 40) (J2000), 
equivalently (l, b) = (106.186 deg, -6.766 deg), 

with a 90% C.L. statistical error of 0.40 deg and an additional systematic 
uncertainty of 0.1 deg (90% containment radius).
The X-ray flux averaged over the scan was 136 +- 30 mCrab (4-10 keV, 
1 sigma error). There was no significant excess flux in the previous transit 
at UT 2014-09-30T12:54.

The nature of the source is quite unknown. Since the source is located 
near the Galactic plane (l ~ -6.8 deg), this event might be an X-ray burst 
from a low mass X-ray binary near the Galactic plane. We tentatively name 
the source GRB 140930A and MAXI J2259+524 (originally, MAXI J2256+527
in the MAXI ML. "New-transient: 115").

E. Gorbovskoy, V. Lipunov, M.Pruzhinskaya,  V.Kornilov, D.Kuvshinov, N.Tyurina, 
N.Shatskiy, P.Balanutsa, A.Kuznetsov, V.V.Chazov, D.Denisenko, 
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University

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

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

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

V.Krushinski, I.Zalozhnih,  A. Popov
Ural Federal 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)



Three MASTER system telescopes (MASTER-Net: http://observ.pereplet.ru) 
located in Blagoveshchensk, Tunka and Kislovodsk have observed GRB140630A 
(Negoro et. al GCN 16855
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 ).

MASTER II  robotic telescope located in Blagoveschensk was pointed to the 
GRB140930A 21 sec after notice time and 6331 sec after trigger time at 
2014-09-30 16:12:34 UT in two polarizations. On our single and coadd 
images we  not found credible optical transient within MAXI error-box 
(Negoro et. al GCN 16855
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 ). The 5-sigma upper limit on single (180 s) 
images has been about 18.1 mag. The 5-sigma upper limit on coadd of 13 
image with total exposure 2340 s is about 19.5m

MASTER II  robotic telescope located in Kislovodsk was pointed to the 
GRB140930A 22 sec after notice time and 6332 sec after trigger time at 
2014-09-30 16:12:35 UT in two polarizations. On our single and coadd 
images we not found credible optical transient within MAXI error-box. The 
5-sigma upper limit on single (180 s) images has been about 18.5 mag. The 
5-sigma upper limit on coadd of first 12 image with total exposure 2160 s 
is about 20.5m

MASTER II  robotic telescope  located in Tunka was pointed to the 
GRB140930A 93 sec after notice time and 6415 sec after trigger time at 
2014-09-30 16:13:58 UT in two polarizations. On our single and coadd 
images we not found credible optical transient within MAXI error-box. The 
5-sigma upper limit on single (180 s) images has been about 17.9 mag. The 
5-sigma upper limit on coadd of 13 image with total exposure 2340 s is 
about 20.0 m

The upper limits received by MASTER are given in the table below:

t_start      | t-t_mid     | exptime | filt | lim  | site | coadd
-------------+-------------+---------+------+------+------+-------
16:12:35.693 | 6485 sec    |     180 | P    | 18.5 | K    |     1
16:12:35.693 | 6485 sec    |     540 | P    | 19.5 | K    |     3
16:19:43.551 | 8075 sec    |    2160 | C    |~20.5 | K    |    12
16:12:34.498 | 6484 sec    |     180 | P    | 18.1 | B    |     1
17:20:44.913 | 12010 sec   |    2520 | C    | 19.5 | B    |    14
16:13:58.211 | 6568 sec    |     180 | P    | 17.9 | T    |     1
16:32:51.181 | 9877 sec    |    2340 | C    |~20.0 | T    |    13

Our white (clear) band is well described by a parity 0.8R+0.2B (USNO B1).


The MASTER-NET coverage map available here:
http://master.sai.msu.ru/static/GRB/GRB140930A/GRB140930A_cm.png

The MASTER image of MAXI error box with upper limit ~20m available here 
(10Mb):
http://master.sai.msu.ru/static/GRB/GRB140930A/GRB140930A_img.jpeg

The message may be cited.