[vsnet-grb-info 16965] GRB 150907A: MAXI/GSC detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  18246
SUBJECT: GRB 150907A: MAXI/GSC detection
DATE:    15/09/07 17:46:13 GMT
FROM:    Motoko Suzuki at RIKEN  <motoko at crab.riken.jp>

Y. E. Nakagawa (JAXA), H. Negoro, (Nihon U.), M. Serino (RIKEN),
M. Ishikawa, S. Nakahira, S. Ueno, H. Tomida,  M. Kimura(JAXA),
T. Mihara, M. Sugizaki,  M. Shidatsu, J. Sugimoto, T. Takagi, M. Matsuoka (RIKEN), 
N. Kawai, Y. Tachibana, T. Yoshii (Tokyo Tech),
A. Yoshida, T. Sakamoto, Y. Kawakubo, H. Ohtsuki (AGU), 
H. Tsunemi, R. Imatani (Osaka U.), M. Nakajima, T. Masumitsu, K. Tanaka (Nihon U.), 
Y. Ueda, T. Kawamuro, T. Hori (Kyoto U.), Y. Tsuboi, S. Kanetou (Chuo U.), 
M. Yamauchi, D. Itoh (Miyazaki U.), K. Yamaoka (Nagoya U.), M. Morii (ISM) 
report on behalf of the MAXI team:

The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray transient source at
16:00:50 UT on 7 September 2015. Assuming that the source flux was constant over the transit,
we obtain the source position at
(R.A., Dec) = (224.845 deg, -47.592 deg) = (14 59 22, -47 35 31) (J2000)
with a 90% C.L. statistical error of 0.06 deg. 
There is an additional systematic uncertainty of 0.1 deg (90% containment radius).
The X-ray flux averaged over the scan was 1464 +- 75 mCrab (4-10keV, 1 sigma error).
There was no significant excess flux in the previous transit at 14:28 UT on 7 September 2015
with an upper limit of 20 mCrab.