TITLE: GCN CIRCULAR NUMBER: 42733 SUBJECT: GRB 251115A: Swift-XRT observations DATE: 25/11/18 10:09:35 GMT FROM: Phil Evans at U of Leicester <pae9@star.le.ac.uk> S. Dichiara (PSU), J.A. Kennea (PSU), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), T. Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB), M.G. Bernardini (INAF-OAB), D.N. Burrows (PSU) and P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the Fermi/LAT-detected burst GRB 251115A in a series of observations tiled on the sky. The total exposure time is 4.9 ks, distributed over 5 tiles; the maximum exposure at a single sky location in the tiling was 2.1 ks. The data were collected between T0+35.6 ks and T0+80.1 ks, and are entirely in Photon Counting (PC) mode. Six 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): 330.1753 = 22h 00m 42.06s Dec (J2000.0): -9.3644 = -09d 21' 51.7" Error: 8.5 arcsec (radius, 90% conf.) Count-rate: (3.7 [+2.2, -1.6])e-3 ct s^-1 Distance: 660 arcsec from Fermi/LAT position. Source 2: RA (J2000.0): 330.0683 = 22h 00m 16.38s Dec (J2000.0): -9.4681 = -09d 28' 05.0" Error: 8.6 arcsec (radius, 90% conf.) Count-rate: (6.2 [+3.9, -2.8])e-3 ct s^-1 Distance: 1100 arcsec from Fermi/LAT position. Source 3: RA (J2000.0): 330.0530 = 22h 00m 12.72s Dec (J2000.0): -9.1976 = -09d 11' 51.3" Error: 5.8 arcsec (radius, 90% conf.) Count-rate: (4.3 [+2.3, -1.7])e-3 ct s^-1 Distance: 437 arcsec from Fermi/LAT position. Flux: (2.26 [+1.23, -0.91])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV) Source 4: RA (J2000.0): 330.2127 = 22h 00m 51.06s Dec (J2000.0): -9.1608 = -09d 09' 38.9" Error: 14.1 arcsec (radius, 90% conf.) Count-rate: (9.6 [+4.4, -3.4])e-3 ct s^-1 Distance: 152 arcsec from Fermi/LAT position. Flux: (3.6 [+1.6, -1.2])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV) Source 6: RA (J2000.0): 329.7737 = 21h 59m 05.69s Dec (J2000.0): -8.8965 = -08d 53' 47.2" Error: 5.6 arcsec (radius, 90% conf.) Count-rate: 0.0113 [+0.0055, -0.0042] ct s^-1 Distance: 1756 arcsec from Fermi/LAT position. Flux: (4.5 [+2.2, -1.7])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV) Source 7: RA (J2000.0): 329.8892 = 21h 59m 33.40s Dec (J2000.0): -8.9944 = -08d 59' 39.8" Error: 6.6 arcsec (radius, 90% conf.) Count-rate: 0.0101 [+0.0049, -0.0038] ct s^-1 Distance: 1218 arcsec from Fermi/LAT position. Flux: (2.63 [+1.28, -0.99])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV) A catalogued source was also detected. The results of the XRT-team automatic analysis of the tiled XRT observations, including a position-specific upper limit calculator, are available at https://www.swift.ac.uk/xrt_products/TILED_GRB00140. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/42733. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...