TITLE: GCN CIRCULAR NUMBER: 14462 SUBJECT: GRB 130427A: MAXI/GSC detection DATE: 13/04/27 15:19:38 GMT FROM: Satoshi Nakahira at JAXA/MAXI T. Kawamuro, M. Shidatsu (Kyoto U.), S. Nakahira (JAXA), H. Negoro (Nihon U.), S. Ueno, H. Tomida, M. Kimura, M. Ishikawa (JAXA), T. Mihara, M. Sugizaki, M. Serino, M. Morii, T. Yamamoto, J. Sugimoto, T. Takagi, M. Matsuoka (RIKEN), N. Kawai, R. Usui, K. Ishikawa, T. Yoshii (Tokyo Tech), A. Yoshida, T. Sakamoto, Y. Nakano (AGU), H. Tsunemi, M. Sasaki (Osaka U.), M. Nakajima, T. Onodera, K. Fukushima, K. Suzuki (Nihon U.), Y. Ueda, M. Shidatsu (Kyoto U.), Y. Ueda (Kyoto U.), Y. Tsuboi, M. Higa (Chuo U.), M. Yamauchi, K. Yoshidome, Y. Ogawa, H. Yamada (Miyazaki U.), K. Yamaoka (Nagoya U.) report on behalf of the MAXI team MAXI/GSC detected the bright GRB 130427A in the scan transit at 2013-04-27T08:42 UT, about 50 min after the trigger by Swift-BAT (Maselli et al. GCN 14448). The one-scan averaged 2-10 keV fluxes were 71 +- 19 mCrab and 23 +- 13 mCrab in the scan transits at 2013-04-27T08:42 and 2013-04-27T10:13, respectively. There were no significant excess fluxes in the previous scan transit at 07:12 UT and in the transit at 11:46 with an upper limit of 30 mCrab for each.