//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18993 SUBJECT: GRB 160206A: MAXI/GSC detection DATE: 16/02/06 07:01:50 GMT FROM: Motoko Suzuki at RIKEN K. Furuya (Miyazaki U.) , Nakahira, M.(JAXA), M. Nakajima (Nihon U.), M. Serino (RIKEN), S. Ueno, H. Tomida, S. Nakahira, M. Ishikawa, Y. E. Nakagawa (JAXA), T. Mihara, M. Sugizaki, 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, H. Ohtsuki Y. Kawakubo (AGU), H. Tsunemi, R. Imatani (Osaka U.), H. Negoro (Nihon U.), 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, D. Itoh, (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 02:52:43 UT on on 2016 Feburary 6. Assuming that the source flux was constant over the transit, we obtain the source position at (R.A., Dec) = (132.696 deg, -36.099 deg) = (08 50 47, -36 05 56) (J2000) with a statistical 90% C.L. elliptical error region with long and short radii of 0.33 deg and 0.3 deg, respectively. The roll angle of long axis from the north direction is 23.0 deg counterclockwise. There is an additional systematic uncertainty of 0.1 deg (90% containment radius). The X-ray flux averaged over the scan was 125 +- 26 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: (R.A., Dec) = (132.055 deg, -35.576 deg) = (08 48 13, -35 34 32) (J2000) (R.A., Dec) = (132.787 deg, -35.291 deg) = (08 51 08, -35 17 28) (J2000) (R.A., Dec) = (133.399 deg, -36.778 deg) = (08 53 35, -36 46 40) (J2000) (R.A., Dec) = (132.642 deg, -37.044 deg) = (08 50 34, -37 02 39) (J2000) There was no significant excess flux in the previous transit at UT 01:20 and in the next transit at 04:25 UT with an upper limit of 20 mCrab for each. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18994 SUBJECT: GRB 160206A: Tiled Swift observations DATE: 16/02/06 15:44:15 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 160206A. Automated analysis of the XRT data will be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00053 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: 18996 SUBJECT: GRB 160206A: Swift-XRT observations DATE: 16/02/06 23:26:02 GMT FROM: Andrea Melandri at INAF-OAB K.L. Page (U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A. Maselli (INAF-IASFPA), L.M. McCauley (PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), C. Pagani (U. Leicester), A.P. Beardmore (U. Leicester) 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 160206A (Furuya et al. GCN Circ. 18993) in a series of observations tiled on the sky. The total exposure time is 3.7 ks, distributed over 4 tiles; the maximum exposure at a single sky location was 1.6 ks. The data were collected between T0+46.2 ks and T0+53.5 ks, and are entirely in Photon Counting (PC) mode. Two uncatalogued X-ray sources have been detected, however none of them is above the RASS limit or shows definitive signs of fading. Therefore, at the present time we cannot identify which, if any, is the afterglow. Details of these sources are given below: Source 1: RA (J2000.0): 132.7319 = 08:50:55.65 Dec (J2000.0): -36.3302 = -36:19:48.5 Error: 4.1 arcsec (radius, 90% conf.) Count-rate: 0.0262 +/- 0.0060 ct s^-1 Flux: (5.8 +/- 1.3)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV) Source 2: RA (J2000.0): 132.5583 = 08:50:13.98 Dec (J2000.0): -36.0137 = -36:00:49.5 Error: 5.8 arcsec (radius, 90% conf.) Count-rate: (5.2 +/- 2.4)e-3 ct s^-1 Flux: (1.04 +/- 0.49)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV) 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_GRB00053. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18997 SUBJECT: GRB 160206A: GROND Observations DATE: 16/02/07 13:20:51 GMT FROM: Corentin Delvaux at MPE T. Kruehler, C. Delvaux , J. Greiner (all MPE Garching) report on behalf of the GROND team: We observed the field of GRB 160206A (Furuya et al., GCN #18993) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at ESO La Silla Observatory (Chile). Observations centered on XRT source #2 (Page et al. 2016, GCN #18996) started at 00:40 UT on 2016-02-07, 22.3 hrs after the GRB trigger. They were performed at an average seeing of 1.5" and at an average airmass of 1.4. We detect no source brighter than the Digitized Sky Survey limiting magnitudes in the 5.8" Swift-XRT error circle. There is one fainter source (r'~22.6 AB mag) at RA(2000.0) = 08:50:14.1, Decl.(2000.0) = -36:00:52, but no statement about variability can be made at this stage. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19000 SUBJECT: GRB 160206A: Swift/UVOT observations DATE: 16/02/07 20:04:48 GMT FROM: Massimiliano de Pasquale at IASF-Palermo M. De Pasquale (PSU) and A. Melandri (INAF-OAB) report on behalf of the Swift/UVOT team: The Swift/UVOT began observing the field of MAXI-detected GRB 160206A (Furuya et al., GCN Circ. 18993) 46.2 ks after the trigger. No optical afterglow consistent with the XRT source 2 given by Page et al. (GCN Circ. 18996) is detected in the UVOT exposures. Preliminary 3-sigma upper limit using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the summed UVOT exposures is: Filter T_start(s) T_stop(s) Exp(s) 3sigma UL Mag u 48081 52769 909 21 Source 1 is found to be consistent with the magnitude 12.3 object TyC 7149 2271-1. These magnitudes are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.47 in the direction of the burst (Schlegel et al. 1998). [GCN OPS NOTE(08feb16): Per author's request, "XRT source 1" was changed to "XRT source 2", and "Source 2 is" was changed to "Source 1 is".] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19008 SUBJECT: GRB 160206A: Kiso/KWFC optical observations DATE: 16/02/10 04:46:44 GMT FROM: Tomoki Morokuma at U of Tokyo Tomoki Morokuma (The University of Tokyo), Nozomu Tominaga (Konan University), Masaomi Tanaka (National Astronomical Observatory of Japan), Akihiro Suzuki (Kyoto University), Motoko Serino (RIKEN), Takanori Sakamoto (Aoyama Gakuin University), and Keiichi Maeda (Kyoto University) report: We took r-band images for the field of GRB 160206A (Furuya et al. 2016, GCN Circ. 18993) 10.5 hours after the trigger with the Kiso Wide Field Camera (KWFC; Sako et al. 2012, SPIE, 8446, 84466L) on the 1.05-m Kiso Schmidt telescope in Japan. Our data were taken in a very low elevation (10-15 degrees) and the detection limits were 17.0 mag (S/N=5, without the Galactic extinction correction). No optical afterglow is detected at the position of Swift XRT source 2 (Page et al. 2016, GCN Circ. 18996) in any of our ten 180-sec exposures. The Swift XRT source 1 (TYC 7149-2271-1) is saturated in all the images and it is difficult to evaluate its time variability. Starting times (UT) of the exposures are summarized as below. date(UT) time t_exp[s] 2016-02-06 13:27:19 180 2016-02-06 13:32:51 180 2016-02-06 13:38:17 180 2016-02-06 13:43:43 180 2016-02-06 13:49:06 180 2016-02-06 13:54:36 180 2016-02-06 14:00:01 180 2016-02-06 14:05:26 180 2016-02-06 14:10:50 180 2016-02-06 14:16:17 180