TITLE: GCN CIRCULAR NUMBER: 41623 SUBJECT: LIGO/Virgo/KAGRA S250831cc: Coverage and upper limits from MAXI/GSC observations DATE: 25/09/01 03:03:21 GMT FROM: Hitoshi Negoro at Nihon University/MAXI team <negoro.hitoshi@nihon-u.ac.jp> H. Negoro, M. Nakajima, K. Takagi (Nihon U.), N. Kawai, T. Mihara, (RIKEN), S. Sugita, M. Serino, Y. Kawakubo, H. Hiramatsu, Y. Kondo (AGU) report on behalf of the MAXI team: We examined MAXI/GSC all-sky X-ray images (2-20 keV) after compact binary merger candidate S250831cc at 2025-08-31 12:30:48.228 UTC. At the trigger time of S250831cc, the high-voltage of MAXI/GSC was on, but the FOV was out of the 90% credible region of the bayestar skymap. The first one-orbit (92 min) scan observation with GSC after the event covered 48% of the 90% credible region of the bayestar skymap from 13:12:46 to 13:24:01 UTC (T0+2518 to T0+3193 sec). No significant new source was found in the region in the one-orbit scan observation. A typical 1-sigma averaged upper limit obtained in one scan observation is 20 mCrab at 2-20 keV. If you require information about X-ray flux by MAXI/GSC at specific coordinates, please contact the submitter of this circular by email. View this GCN Circular online at https://gcn.nasa.gov/circulars/41623. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...