TITLE:   GCN CIRCULAR
NUMBER:  40910
SUBJECT: GRB 250702B,C,D,E / EP 250702a: MAXI/GSC detection
DATE:    25/07/03 09:47:38 GMT
FROM:    Yuta Kawakubo at Aoyama Gakuin University <kawakubo@phys.aoyama.ac.jp>

Y. Kawakubo, M. Serino (AGU), H. Negoro, M. Nakajima, , K. Takagi, H. Takahashi, 
K. Tatano, H. Nishio (Nihon U.), T. Mihara, T. Tamagawa, N. Kawai, M. Matsuoka (RIKEN),
T. Sakamoto, S. Sugita, H. Hiramatsu, Y. Kondo, A. Yoshida (AGU),
Y. Tsuboi, H. Sugai, N. Nagashima (Chuo U.),
M. Shidatsu, Y. Niida, C. Kang, T. Nakamoto (Ehime U.),
I. Takahashi, Y. Yatsu (Science Tokyo),
S. Nakahira, S. Ueno, H. Tomida, M. Ishikawa, S. Ogawa, M. Kurihara (JAXA),
Y. Ueda, K. Fujiwara (Kyoto U.),
M. Yamauchi, M. Nishio, C. Hiraizumi (Miyazaki U.),
K. Yamaoka (Nagoya U.),
M. Sugizaki (Kanazawa U.),
W. Iwakiri (Chiba U.),
T. Kawamuro (Osaka U.),
S. Yamada (Tohoku U)

We report on the MAXI/GSC detection of an X-ray transient source on July 2, 2025 (MJD 60858) associated with GRB 250702B,C,D,E/EP250702a.

The source was clearly detected at three scan transits from 2025-07-02T12:59 UT 
to 2025-07-02T16:15.

Assuming that the source flux was constant over the three transits, we obtain the
source position at (284.462 deg, -7.936 deg) = (18 57 50, -07 56 09) (J2000)
with a statistical 90% C.L. elliptical error region 
with long and short radii of 0.34 deg and 0.24 deg, respectively.
The roll angle of the long axis from the north direction is 54.0 deg counterclockwise.
There is an additional systematic uncertainty of 0.1 deg (90% containment radius).
The X-ray flux averaged over the three scans was 54 +- 11 mCrab.  

The time and the source position determined by the MAXI observations are consistent 
with GRB 250702B, C, D, E, observed by Fermi-GBM (GCN 40883, 40885, 40886, 40890, 40891),
the source localization skymap provided by Swift/BAT-GUANO (GCN 40903)
and EP250702a observed by the Einstein Probe/WXT, FXT (GCN 40906). 

Follow-up observations are encouraged.