TITLE: GCN CIRCULAR NUMBER: 18525 SUBJECT: GRB 151027A: MAXI/GSC detection DATE: 15/10/29 11:01:12 GMT FROM: H. Negoro at Nihon U. T. Masumitsu, H. Negoro, (Nihon U.), N. Kawai (Tokyo Tech), T. Sakamoto (AGU), S. Ueno, H. Tomida, S. Nakahira, M. Kimura, M. Ishikawa, Y. E. Nakagawa (JAXA), T. Mihara, M. Sugizaki, M. Serino, M. Shidatsu, J. Sugimoto, T. Takagi, M. Matsuoka (RIKEN), T. Yoshii, Y. Tachibana (Tokyo Tech), A. Yoshida, Y. Kawakubo, H. Ohtsuki (AGU), H. Tsunemi, R. Imatani (Osaka U.), M. Nakajima, K. Tanaka (Nihon U.), Y. Ueda, T. Kawamuro, T. Hori (Kyoto U.), Y. Tsuboi, S. Kanetou (Chuo U.), M. Yamauchi, D. Itoh (Miyazaki U.), K. Yamaoka (Nagoya U.), M. Morii (ISM) report on behalf of the MAXI team: MAXI/GSC performed scanning observations at the region of GRB 151027A (Maselli et al. GCN 18478) for 48 sec each at the centroid time 03:38:56, 1168 s before the Swift trigger, and 05:11:32, 4388 s after the Swift trigger. No positive 4-10 keV flux was obtained at the former scan transit with the 3 sigma upper limit of 0.037 photons/cm2/s (~ 31 mCrab). At the latter scan transit, the 4-10 keV flux was 0.0166 +/- 0.0175 photons/cm2/s (~ 14 +/- 15 mCrab). The detection is not significant, but the flux is consistent with the interpolation from the Swift/XRT light curve (V. D'Elica et al. #18509).