//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20481 SUBJECT: GRB 170117A: Swift ToO observations DATE: 17/01/18 02:56:18 GMT FROM: Phil Evans at U of Leicester P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a ToO observation of the Swift/BAT GRB 170117A. Automated analysis of the XRT data will be presented online at http://www.swift.ac.uk/ToO_GRBs/00020728 Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. These are not necessarily related to the Swift/BAT event. 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: 20482 SUBJECT: GRB 170117A: Swift-XRT observations DATE: 17/01/18 21:43:57 GMT FROM: Andrea Melandri at INAF-OAB J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), B. Mingo (U. Leicester), A.P. Beardmore (U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A. Melandri (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 Swift/BAT-detected burst GRB 170117A, collecting 2.9 ks of Photon Counting (PC) mode data between T0+86.3 ks and T0+116.0 ks. No X-ray sources have been detected consistent with being within 296 arcsec of the Swift/BAT position. The 3-sigma upper limit in the field ranges from ~0.003 to ~0.004 ct s^-1, corresponding to a 0.3-10 keV observed flux of 1.3e-13 to 1.8e-13 erg cm^-2 s^-1 (assuming a typical GRB spectrum). An uncatalogued was detected, however this was too far from the GRB position to be the afterglow. The results of the XRT-team automatic analysis of the XRT observations, including a position-specific upper limit calculator, are available at http://www.swift.ac.uk/ToO_GRBs/00020728. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20484 SUBJECT: GRB 170117A: Swift/UVOT Upper Limits DATE: 17/01/19 12:38:02 GMT FROM: Alice Breeveld at MSSL-UCL A. A. Breeveld (UCL-MSSL) and A. Melandri (INAF-OAB) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 170117A 86251 s after the BAT trigger (Palmer, GCN Circ. 20480). No optical afterglow consistent with the BAT position given in that circular is detected in the initial UVOT exposures. The preliminary 3-sigma upper limit using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial summed exposures is: Filter T_start(s) T_stop(s) Exp(s) Mag white 86251 116034 2654 >22.0 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.35 in the direction of the burst (Schlegel et al. 1998).