//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20203 SUBJECT: GRB 161123A: MAXI/GSC detection DATE: 16/11/23 04:51:45 GMT FROM: Motoko Suzuki at RIKEN C. Hanyu (Miyazaki U.), S. Nakahira (JAXA), H. Negoro (Nihon U.), S. Ueno, H. Tomida, M. Ishikawa, Y. Sugawara (JAXA), Y. E. Nakagawa (JAMSTEC), T. Mihara, M. Sugizaki, M. Serino, 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, T. Sakamoto, Y. Kawakubo, 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, S. Oda (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 03:05:58 UT on 2016 November 23. The X-ray flux averaged over the scan was 149 +- 26 mCrab(4.0-10.0keV, 1 sigma error). Without assumptions on the source constancy,we obtain a rectangular error box for the transient source with the following corners: (R.A., Dec) = (32.229, -40.884) deg = (02 08 54, -40 53 02) (J2000) (R.A., Dec) = (31.566, -40.860) deg = (02 06 15, -40 51 36) (J2000) (R.A., Dec) = (32.268, -38.340) deg = (02 09 04, -38 20 24) (J2000) (R.A., Dec) = (32.905, -38.394) deg = (02 11 37, -38 23 39) (J2000) There was no significant excess flux in the previous transit at UT 01:33 and in the next transit at 04:38 UT with an upper limit of 20 mCrab for each. [GCN OPS NOTE(23nov16): Per author's request, the Subject was corrected from 151123A to 161123A.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20204 SUBJECT: GRB 161123A: Tiled Swift observations DATE: 16/11/23 09:15:19 GMT FROM: Phil Evans at U of Leicester P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a series of observations, tiled on the sky, of the MAXI GRB 161123A. Automated analysis of the XRT data will be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00061 Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. The probability of finding serendipitous sources, unrelated to the MAXI event is high: any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration. Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8). This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20206 SUBJECT: GRB 161123A: Swift-XRT observations DATE: 16/11/23 16:12:34 GMT FROM: Andy Beardmore at U Leicester A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), L.M. McCauley (PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), A.P. Beardmore (U. Leicester), S.L. Gibson (U. Leicester), P. D'Avanzo (INAF-OAB) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the MAXI-detected burst GRB 161123A (Hanyu et al. GCN Circ. 20203) in a series of observations tiled on the sky. The total exposure time is 2.6 ks, distributed over 7 tiles; the maximum exposure at a single sky location was 825 s. The data were collected between T0+21.8 ks and T0+28.0 ks, and are entirely in Photon Counting (PC) mode. No X-ray sources have been detected. The 3-sigma upper limit in the field (not including the regions where the tiles overlap) ranges from ~0.02 to ~0.05 ct s^-1, corresponding to a 0.3-10 keV observed flux of 8.2e-13 to 1.9e-12 erg cm^-2 s^-1 (assuming a typical GRB spectrum). The results of the XRT-team automatic analysis of the tiled XRT observations, including a position-specific upper limit calculator, are available at http://www.swift.ac.uk/xrt_products/TILED_GRB00061. This circular is an official product of the Swift-XRT team.