TITLE:   GCN CIRCULAR
NUMBER:  34544
SUBJECT: MAXI/GSC detection of Swift J1727.8-1613 (GRB 230824A)
DATE:    23/08/25 02:25:47 GMT
FROM:    Motoko Serino at Aoyama Gakuin U. <serino@phys.aoyama.ac.jp>

H. Negoro (Nihon U.), M. Serino (AGU), M. Nakajima, K. Kobayashi, M. Tanaka, Y. Soejima, Y. Kudo (Nihon U.), 
T. Mihara, T. Kawamuro, S. Yamada, T. Tamagawa, N. Kawai, M. Matsuoka (RIKEN), 
T. Sakamoto, S. Sugita, H. Hiramatsu, H. Nishikawa, A. Yoshida (AGU), 
Y. Tsuboi, S. Urabe, S. Nawa, N. Nemoto (Chuo U.), M. Shidatsu (Ehime U.), 
I. Takahashi, M. Niwano, S. Sato, N. Higuchi, Y. Yatsu (Tokyo Tech), 
S. Nakahira, S. Ueno, H. Tomida, M. Ishikawa, S. Ogawa, T. Kurihara (JAXA), 
Y. Ueda, K. Setoguchi, T. Yoshitake, Y. Nakatani (Kyoto U.), 
M. Yamauchi, Y. Hagiwara, Y. Umeki, Y. Otsuki (Miyazaki U.), 
K. Yamaoka (Nagoya U.), Y. Kawakubo (LSU), M. Sugizaki (NAOC), and W. Iwakiri (Chiba U.) 
report on behalf of the MAXI team:

 The MAXI/GSC has detected the hard X-ray transient  Swift J1727.8-1613 (GRB 230824A: 
GCN #34536, #34537) since the scan transit at 10:20 on 2023 August 24.
The source flux is increasing rapidly, reaching more than 2 Crab at 10-20 keV at 21:10 and
22:44, which supports the possibility that the source is a Galactic transient, not a GRB 
(GCN #23540).
 The hard and rapid variations suggest that the source is a V404 Cyg like object.
Followup observations are highly encouraged. 
We cross-post this report to the ATel and the GCN.