{
  "bibcode": "2013GCN.14594....1K",
  "body": "D. Kocevski (NASA/GSFC/ORAU), F. E. Marshall (NASA/GSFC), \nM. De Pasquale (MSSL-UCL), P. D'Avanzo (INAF-OAB), \nand A. Melandri (INAF-OAB) report on behalf of the Swift team:\n\nThe Swift began tiling observations of the field of GRB 130505B\n16 hours after the MAXI trigger (Serino et al., GCN Circ. 14586).\nA bright source not in the DSS is seen in the UVOT observation\nat a preliminary position of \n   RA(J2000)  =    09:17:22.18 = 139.34124\n   DEC(J2000) =   +01:42:03.1  =  +1.70085\nwith a 90%-confidence error radius of about 0.6 arc sec.\nIt is not possible to determine whether the source is varying\nwith the currently available data.\n\nThe position is consistent with that of SDSS J091721.89+014203.2,\nbut more than 5 magnitudes brighter in the u band.\nThe SDSS source could be the host galaxy for the burst,\nor could indicate that the MAXI source is a galactic transient.\n\nThe preliminary detection using the UVOT photometric system\n(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the exposure is:\n\nFilter         T_start(s)   T_stop(s)      Exp(s)        Mag\nu                58617        59042         425        18.0 +/- 0.1\n\nThe magnitude is not corrected for the Galactic extinction\ndue to the reddening of E(B-V) = 0.024 in the direction of the burst\n(Schlegel et al. 1998).\n\nWe have also analysed 426 s of Swift-XRT data from 58.6 ks \nto 59.0 ks after the MAXI trigger. The data are all in \nPhoton Counting (PC) mode. A preliminary\nanalysis reveals the presence of a source at the following position \nRA, Dec = 139.34180, +1.70215 which is equivalent to:\n\nRA (J2000): 09 17 22.03\nDec(J2000): +01 42 07.7\n\nwith an uncertainty of 4.5 arcsec (radius, 90% confidence). \nThis position is consistent with the UVOT one. The observed count rate \nis (3.0 +/- 1.0) x 10^-2 cts/s.  Given the low significance of \nthe detection, at the present stage, it is not possible to determine \nwhether the source is variable.\n\nAutomated analysis of the XRT data can be found online at\nhttp://www.swift.ac.uk/xrt_products/TILED_GRB00015/\n\nDetails of the XRT automated analysis methods are detailed in \nEvans et al. (2007, A&A, 469, 379; and 2009, MNRAS, 397, 1177).\n\nAdditional observations with Swift are scheduled. Observations\nwith other observatories of this interesting object are encouraged.",
  "circularId": 14594,
  "createdOn": 1367882151000,
  "email": "femarsha@khamseen.gsfc.nasa.gov",
  "subject": "GRB 130505B: Swift Candidate Afterglow",
  "submitter": "Frank Marshall at GSFC  <femarsha@khamseen.gsfc.nasa.gov>",
  "eventId": "GRB 130505B"
}