TITLE: GCN CIRCULAR NUMBER: 14586 SUBJECT: GRB 130505B: MAXI/GSC detection DATE: 13/05/06 09:23:09 GMT FROM: Motoko Suzuki at RIKEN M. Serino (RIKEN), H. Negoro (Nihon U.), S. Ueno, H. Tomida, S. Nakahira, M. Kimura, M. Ishikawa (JAXA), T. Mihara, M. Sugizaki, 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, Y. Kawakubo (AGU), H. Tsunemi, M. Sasaki (Osaka U.), M. Nakajima, T. Onodera, K. Fukushima, K. Suzuki (Nihon U.), Y. Ueda, M. Shidatsu, T. Kawamuro (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 At 2013-05-05T23:54 UT, the MAXI/GSC detected an uncatalogued X-ray transient source. Assuming a constant source flux over the scan transit, we obtain the source position at (R.A., Dec.) = (139.500 deg 1.500 deg) = (09 18 00, +01 30 00)(J2000) with a 90% C.L. statistical error of 0.3 deg and an additional systematic uncertainty of 0.1 deg (90% containment radius). The averaged X-ray flux was 160 +/- 40 mCrab (4-10 keV). There were no significant excess fluxes at the previous and followed scan transits at 2013/05/05 22:20 UT and 2013/05/06 01:26 UT, respectively, with an upper limit of 20 mCrab for each.