TITLE: GCN CIRCULAR NUMBER: 19793 SUBJECT: GRB 160814A: MAXI/GSC detection DATE: 16/08/15 01:15:00 GMT FROM: Takanori Sakamoto at AGU Y. Kawakubo (AGU), M. Serino (RIKEN), T. Sakamoto (AGU), S. Nakahira (JAXA), H. Negoro (Nihon U.), S. Ueno, H. Tomida, M. Ishikawa, Y. Sugawara (JAXA), Y. E. Nakagawa (JAMSTEC), T. Mihara, M. Sugizaki, W. Iwakiri, M. Shidatsu, J. Sugimoto, T. Takagi, M. Matsuoka (RIKEN), N. Kawai, N. Isobe, S. Sugita, T. Yoshii, Y. Tachibana, Y. Ono, T. Fujiwara, S. Harita, Y. Muraki (Tokyo Tech), A. Yoshida, Y. Kitaoka (AGU), H. Tsunemi, R. Shomura (Osaka U.), M. Nakajima, K. Tanaka, T. Masumitsu, T. Kawase (Nihon U.), Y. Ueda, T. Kawamuro, T. Hori, A. Tanimoto (Kyoto U.), Y. Tsuboi, Y. Nakamura, R. Sasaki (Chuo U.), M. Yamauchi, K. Furuya (Miyazaki U.), K. Yamaoka (Nagoya U.) report on behalf of the MAXI team: The MAXI/GSC nova-alert system triggered a bright uncatalogued X-ray transient source at 21:12:55 UT on 2016 August 14. We obtain a rectangular error box for the transient source at the center position of (R.A., Dec) = (136.074 deg, -20.960 deg) = (09 04 17, -20 57 36) (J2000) with the following corners: (136.030, -21.250) deg = (09 04 07, -21 14 59) (J2000) (135.790, -21.121) deg = (09 03 09, -21 07 16) (J2000) (136.304, -20.423) deg = (09 05 12, -20 25 23) (J2000) (136.542, -20.552) deg = (09 06 10, -20 33 08) (J2000) There is an additional systematic uncertainty of 0.1 deg (90% containment radius). The X-ray flux averaged over the scan was 413 +- 40 mCrab (4.0-10.0keV, 1 sigma error). There was no significant excess flux in the previous transit at 19:40 and in the next transit at 22:45 UT with an upper limit of 20 mCrab for each.