[vsnet-grb-info 15641] GRB 141020B: MAXI/GSC detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16930
SUBJECT: GRB 141020B: MAXI/GSC detection
DATE:    14/10/20 13:38:33 GMT
FROM:    Motoko Suzuki at RIKEN  <motoko at crab.riken.jp>

R. Imatani (Osaka U.), M. Serino (RIKEN), S. Nakahira (JAXA), T. Sakamoto (AGU),
S. Ueno, H. Tomida, M. Kimura, M. Ishikawa, Y. E. Nakagawa (JAXA),
T. Mihara, M. Sugizaki, M. Morii, J. Sugimoto, T. Takagi, A. Yoshikawa, M. Matsuoka (RIKEN),
N. Kawai, T. Yoshii, Y. Tachibana (Tokyo Tech),
A. Yoshida, Y. Kawakubo, H. Ohtsuki (AGU),
H. Tsunemi, D. Uchida (Osaka U.),
H. Negoro, 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, D. Itoh (Miyazaki U.),
K. Yamaoka (Nagoya U.)
report on behalf of the MAXI team:

The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray transient source at 10:59:25 UT.
Assuming that the source flux was constant over the transit,
we obtain the source position at
(R.A., Dec) = (214.296 deg, 7.984 deg) = (14 17 11, +07 59 02) (J2000)
with a statistical 90% C.L. elliptical error region
with long and short radii of 0.36 deg and 0.25 deg respectively.
The roll angle of long axis from the north direction is 57.0 deg counterclockwise.
There is an additional systematic uncertainty of 0.1 deg (90% containment radius).
The X-ray flux averaged over the scan was 114 +- 24 mCrab
(4-10keV, 1 sigma error).
There was no significant excess flux in the previous transit at 09:26 UT
and in the next transit at 12:32 UT 
with an upper limit of 20 mCrab for each.  

Since the source is only 21 degrees from the Sun (Sun constrained for next 45 days), 
no immediate Swift observation is possible.