[vsnet-grb-info 25650] GRB 200517A: MAXI/GSC detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  27750
SUBJECT: GRB 200517A:  MAXI/GSC detection
DATE:    20/05/17 12:46:55 GMT
FROM:    Motoko Serino at RIKEN/MAXI  <motoko at crab.riken.jp>

M. Niwano (Tokyo Tech), H. Negoro (Nihon U.), M. Serino (AGU),
M. Nakajima, M. Aoki, K. Kobayashi, R. Takagi, K, Asakura, K, Seino, S. Mokumoto (Nihon U.),
T. Mihara, C. Guo, Y. Zhou, T. Tamagawa, M. Matsuoka (RIKEN),
T. Sakamoto, S. Sugita, H. Nishida, A. Yoshida (AGU),
Y. Tsuboi, W. Iwakiri, R. Sasaki, H. Kawai, Y. Okamoto, S. Kitakoga (Chuo U.),
M. Shidatsu (Ehime U.),
N. Kawai, R. Adachi (Tokyo Tech),
S. Nakahira, Y. Sugawara, S. Ueno, H. Tomida, M. Ishikawa, M. Tominaga, T. Nagatsuka (JAXA),
Y. Ueda, S. Yamada, S. Ogawa, K. Setoguchi, T. Yoshitake (Kyoto U.),
H. Tsunemi (Osaka U.),
M. Yamauchi, K. Kurogi, K. Miike (Miyazaki U.),
T. Kawamuro (NAOJ),
K. Yamaoka (Nagoya U.),
Y. Kawakubo (LSU),
M. Sugizaki (NAOC) 
report on behalf of the MAXI team:

The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray transient source at 11:27:21 UT .
We obtained the source position at
(R.A., Dec) = (17.230 deg, -50.745 deg) = (01 08 55, -50 44 41) (J2000)
with a rectangular error box with the following corners:
(15.411, -49.816) deg = (01 01 38, -49 48 57) (J2000)
(15.002, -50.346) deg = (01 00 00, -50 20 45) (J2000)
(18.572, -51.401) deg = (01 14 17, -51 24 03) (J2000)
(18.949, -50.859) deg = (01 15 47, -50 51 32) (J2000)
There is an additional systematic uncertainty of 0.1 deg (90% containment radius).
The X-ray flux averaged over the scan was 198 +- 33 mCrab
(4.0-10.0keV, 1 sigma error).
There was no significant excess flux in the previous transit at 09:54 UT
with an upper limit of 20 mCrab.