GCN Circular 38462

GRB 241207C: MAXI/GSC detection

M. Nakajima (Nihon U.), M. Serino (AGU), W. Iwakiri (Chiba U.),
H. Negoro, Y. Kudo, H. Shibui, K. Takagi, H. Takahashi, K. Tatano, H. Nishio (Nihon U.),
T. Mihara, T. Kawamuro, S. Yamada, S. Wang, T. Tamagawa, N. Kawai, M. Matsuoka (RIKEN),
T. Sakamoto, S. Sugita, Y. Kawakubo, H. Hiramatsu, H. Nishikawa, Y. Kondo, S. Sasao, A. Yoshida (AGU),
Y. Tsuboi, H. Sugai, N. Nagashima (Chuo U.),
M. Shidatsu, Y. Niida (Ehime U.),
I. Takahashi, M. Niwano, N. Higuchi, Y. Yatsu (Tokyo Tech),
S. Nakahira, S. Ueno, H. Tomida, M. Ishikawa, S. Ogawa, M. Kurihara (JAXA),
Y. Ueda, Y. Okada, K. Fujiwara (Kyoto U.),
M. Yamauchi, Y. Otsuki, T. Hasegawa, M. Nishio (Miyazaki U.),
K. Yamaoka (Nagoya U.),
M. Sugizaki (Kanazawa U.),

report on behalf of the MAXI team:
The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray transient source at 22:20:07 UT.
Assuming that the source flux was constant over the transit,
we obtain the source position at
(R.A., Dec) = (306.821 deg, -23.399 deg) = (20 27 17, -23 23 56) (J2000)
with a statistical 90% C.L. elliptical error region
with long and short radii of 0.41 deg and 0.34 deg, respectively.
The roll angle of long axis from the north direction is 132.0 deg counterclockwise.
There is an additional systematic uncertainty of 0.1 deg (90% containment radius).
The X-ray flux averaged over the scan was 91 +- 22 mCrab
(4.0-10.0keV, 1 sigma error).
There was no significant excess flux in the previous transit at 20:47 UT 
and in the next transit at 23:53 UT with an upper limit of 20 mCrab for each.