TITLE: GCN CIRCULAR NUMBER: 18801 SUBJECT: GRB 160102A: MAXI/GSC detection DATE: 16/01/02 04:49:22 GMT FROM: H. Negoro at Nihon U. D. Itoh (Miyazaki U.), S. Nakahira (JAXA), H. Negoro (Nihon U.), H. Tomida, M. Ishikawa, Y. E. Nakagawa (JAXA), T. Mihara, M. Sugizaki, M. Serino, M. Shidatsu, J. Sugimoto, T. Takagi, M. Matsuoka (RIKEN), N. Kawai, M. Arimoto, T. Yoshii, Y. Tachibana, Y. Ono, T. Fujiwara (Tokyo Tech), A. Yoshida, T. Sakamoto, Y. Kawakubo, H. Ohtsuki (AGU), H. Tsunemi, R.Imatani (Osaka U.), M. Nakajima, K. Tanaka, T. Masumitsu (Nihon U.), Y. Ueda, T. Kawamuro, T. Hori, A. Tanimoto (Kyoto U.), Y. Tsuboi, S. Kanetou, Y. Nakamura, R. Sasaki (Chuo U.), M. Yamauchi, K. Furuya (Miyazaki U.), K. Yamaoka (Nagoya U.), M. Morii (ISM) report on behalf of the MAXI team: The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray transient source at 03:39:16 UT on 2016 January 2. Assuming that the source flux was constant over the transit, we obtain the source position at (R.A., Dec) = (80.840 deg, -21.041 deg) = (05 23 21, -21 02 27) (J2000) with a statistical 90% C.L. elliptical error region and with long and short radii of 0.19 deg and 0.14 deg, respectively. The roll angle of long axis from the north direction is 180.0 deg counterclockwise. Theres an additional systematic uncertainty of 0.1 deg (90% containment radius). The X-ray flux averaged over the scan was 265 +- 32 mCrab (4-10keV, 1 sigma error). Without assumptions on the source constancy,we obtain a rectangular error box for the transient source with the following corners: (80.157 deg, -20.852 deg) = (05 20 37, -20 51 07) (J2000) (80.155 deg, -21.225 deg) = (05 20 37, -21 13 28) (J2000) (81.765 deg, -21.221 deg) = (05 27 03, -21 13 16) (J2000) (81.756 deg, -20.849 deg) = (05 27 01, -20 50 55) (J2000) There was no significant excess flux in the previous transit at UT 02:06 with an upper limit of 20 mCrab for each. For more information on this burst: http://www.maxi.riken.jp/alert/novae/7389136382/7389136382.htm