TITLE: GCN CIRCULAR NUMBER: 13436 SUBJECT: GRB 120711A: MAXI/GSC detection DATE: 12/07/11 10:14:08 GMT FROM: Mikio Morii at Tokyo Inst Tech M. Serino (RIKEN), M. Morii(Tokyo Tech), S. Nakahira (JAXA), N. Kawai, R. Usui, K. Ishikawa, T. Yoshii (Tokyo Tech), S. Ueno, H. Tomida, M. Ishikawa (JAXA), T. Mihara, M. Sugizaki, T. Yamamoto, J. Sugimoto, M. Matsuoka (RIKEN), A. Yoshida (AGU), H. Tsunemi, M. Kimura (Osaka U.), H. Negoro, M. Nakajima, M. Asada, H. Sakakibara, N. Serita (Nihon U.), Y. Ueda, K. Hiroi, M. Shidatsu, R. Sato (Kyoto U.), Y. Tsuboi, M. Higa (Chuo U.) M. Yamauchi, Y. Nishimura, T. Hanayama, K. Yoshidome (Miyazaki U.), K. Yamaoka (Waseda U.) report on behalf of the MAXI team: MAXI/GSC triggered at 2012-07-11T02:45:12 UT on a bright uncatalogued X-ray transient source. The transient emission lasted at least 50 seconds within the 67 second long triangular transit response of MAXI/GSC. Assuming that the source flux was constant over the transit, we obtain the source position at (R.A., Dec) = (94.04 deg, -71.09 deg) = (06 16 10, -71 05 37)(J2000) with a 90% C.L. statistical error of 12 arcmin and an additional systematic uncertainty of 0.1 deg (90% containment radius). Without assuming the source constancy, we obtain a rectangular error box (90%C.L.) with the following corners: (R.A., Dec) = (+94.86 deg, -70.99 deg) = (06 19 29, -70 59 26)(J2000) (R.A., Dec) = (+94.93 deg, -71.21 deg) = (06 19 44, -71 12 23)(J2000) (R.A., Dec) = (+91.53 deg, -71.22 deg) = (06 06 06, -71 13 27)(J2000) (R.A., Dec) = (+91.52 deg, -71.01 deg) = (06 06 05, -71 00 26)(J2000) This error region includes the position of GRB 120711A reported by Lacluyze et al. (GCN #13430) and Gotz et al. (GCN #13434). Fixing the source position to that of GRB 120711A, we obtained the light curve corrected with the transit response within the GSC scan. It was variable within the scan, and the peak flux was 610 +- 130 (mCrab, 2-20 keV) on 2012-07-11 02:44:54 UT.