[vsnet-grb-info 22838] GRB 190701A: MAXI/GSC detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  24937
SUBJECT: GRB 190701A: MAXI/GSC detection
DATE:    19/07/01 11:55:46 GMT
FROM:    Motoko Serino at RIKEN/MAXI  <motoko at crab.riken.jp>

K. Setoguchi (Kyoto U.), H. Negoro, M. Nakajima, W. Maruyama, M. Aoki, K. Kobayashi (Nihon U.), 
S. Nakahira, T. Mihara, T. Tamagawa, M. Matsuoka (RIKEN),
T. Sakamoto, M. Serino, S. Sugita, H. Nishida, A. Yoshida (AGU), 
Y. Tsuboi, W. Iwakiri, R. Sasaki, H. Kawai, T. Sato (Chuo U.), 
M. Shidatsu (Ehime U.),
N. Kawai, M. Sugizaki, M. Oeda, K. Shiraishi (Tokyo Tech), 
S. Ueno, H. Tomida, M. Ishikawa, Y. Sugawara, N. Isobe, R. Shimomukai, M. Tominaga (JAXA), 
Y. Ueda, A. Tanimoto, S. Yamada, S. Ogawa, T. Yoshitake (Kyoto U.), 
H. Tsunemi, T. Yoneyama, K. Asakura, S. Ide (Osaka U.), 
M. Yamauchi, S. Iwahori, Y. Kurihara, K. Kurogi, K. Miike (Miyazaki U.), 
T. Kawamuro (NAOJ), 
K. Yamaoka (Nagoya U.),
Y. Kawakubo (LSU)
report on behalf of the MAXI team:

The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray transient 
source at 09:46:42 UT on July 1, 2019.
Assuming that the source flux was constant over the transit,
we obtain the source position at
(R.A., Dec) = (27.548 deg, 58.852 deg) = (01 50 11, +58 51 06) (J2000)
with a 90% C.L. statistical error of 0.16 deg and an additional systematic uncertainty 
of 0.1 deg (90% containment radius).
Without assumptions on the source constancy, we obtain a rectangular error box
for the transient source with the following corners: 
(25.762, 59.105) deg = (01 43 02, +59 06 17) (J2000)
(25.721, 58.781) deg = (01 42 53, +58 46 51) (J2000)
(29.166, 58.620) deg = (01 56 39, +58 37 11) (J2000)
(29.239, 58.942) deg = (01 56 57, +58 56 31) (J2000).
This position is consistent with that of GRB 190701A detected 
by Swift (Ukwatta et al., GCN 24934, Evans et al., GCN 24935).

The X-ray flux averaged over the scan was 416 +- 39 mCrab
(4.0-10.0keV, 1 sigma error).

There was no significant excess flux in the previous transit at UT 08:14 
and in the next transit at 11:19 UT with an upper limit of 20 mCrab for each.