TITLE: GCN CIRCULAR NUMBER: 21741 SUBJECT: LIGO/Virgo G299232 : MAXI/GSC observations DATE: 17/08/29 05:46:53 GMT FROM: Satoshi Sugita at Tokyo Inst. of Tech. S. Sugita, N. Kawai (Tokyo Tech), M. Serino (RIKEN), H. Negoro (Nihon U.), S. Ueno, H. Tomida, M. Ishikawa, Y. Sugawara, N.Isobe, R. Shimomukai (JAXA), T. Mihara, M. Sugizaki, S. Nakahira, W. Iwakiri, M. Shidatsu, M. Matsuoka (RIKEN), T. Yoshii, Y. Tachibana, S. Harita, Y. Muraki, K. Morita (Tokyo Tech), A. Yoshida, T. Sakamoto, Y. Kawakubo, Y. Kitaoka, T. Hashimoto (AGU), H. Tsunemi, T. Yoneyama (Osaka U.), M. Nakajima, T. Kawase, A. Sakamaki (Nihon U.), Y. Ueda, T. Hori, A. Tanimoto, S. Oda (Kyoto U.), Y. Tsuboi, Y. Nakamura, R. Sasaki (Chuo U.), M. Yamauchi, C. Hanyu, K, Hidaka (Miyazaki U.), T. Kawamuro (NAOJ), K. Yamaoka (Nagoya U.) report on behalf of the MAXI team: We examined the MAXI/GSC all-sky X-ray images (2-20 keV) obtained in the orbit and the day after the LVC trigger G299232 at 2017-08-25 13:13:31 UTC (GCN 21693). At the trigger time of G299232, the high-voltage of MAXI/GSC was off, and it was turned on at T0+1480 sec. GSC scanned more than 56% of the whole sky in the 92-min orbit, which includes 69.0% of the 90% region in the bayestar skymap. scanned from 13:13:31 UTC. One day image obtained between 08-25 13:13:31 and 08-26 12:03:01 UTC covers 99.0% of the 90% region in the bayestar skymap. No significant new source was found in these images and the 2-20 keV averaged photon counts in the skymap region is 0.41 counts/cm2/sec. The 3-sigma averaged upper limits obtained from the one-scan and one-day images in the bayestar skymap are 39 and 12 mCrab, respectively (see Serino et al., 2017 for the upper limit calculation). If you require information of X-ray flux by MAXI/GSC at specific coordinates, please contact the submitter of this circular by email.