{
  "bibcode": "2012GCN.13709....1B",
  "body": "W. H. Baumgartner (GSFC/UMBC), V. D'Elia (ASDC), M. Siegel (PSU),\nF. E. Marshall (NASA/GSFC), J. L. Racusin (NASA/GSFC), J. A. Kennea\n(PSU), and D. N. Burrows (PSU) report on behalf of the Swift team:\n\nSwift observed the the error circle for the Fermi/LAT and IPN detected\nGRB 120831A (Vianello et al., GCN Circ. 13704, Hurley et al. GCN Circ\n13705). Two 4 ks XRT observations were taken to cover the IPN error\nregion, beginning about 60 ks and 72 ks after the burst.  Together\nthese two XRT observations cover 100% of the IPN error box.\n\nOne uncatologed X-ray source is found within the IPN error box at RA,\nDec = 88.501667, -28.701333 which is equivalent to:\n\nRA (J2000): 05h 54m 00.40s\nDec (J2000): -28d 42' 04.8\"\n\nwith an uncertainty of 8 arcsec (radius, 90% confidence).  The XRT\nsource has a significance of 2.5 sigma, and the count rate during this\nobservation in photon counting mode was 2.53e-3 +/- 1.0e-3 cts sec^-1.\n\nThe Swift/UVOT began settled observations of the first of the two\nfields for GRB 120830A 59804 s after the LAT/IPN trigger.  No data are\navailable yet for the second field.  A source consistent with the XRT\nsource is detected in the initial UVOT exposures.  There is no\ncorresponding source in the USNO-B1.0 catalog.\n\nThe preliminary UVOT position is:\n     RA  (J2000) =  05:54:00.65 =  88.50270 (deg.)\n     Dec (J2000) = -28:42:06.4  = -28.70178 (deg.)\nwith an estimated uncertainty of 0.55 arc sec. (radius, 90% confidence).\n\nPreliminary results using the UVOT photometric system (Breeveld et\nal. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:\n\nFilter         T_start(s)   T_stop(s)      Exp(s)           Mag\nwhite            59804        67310         3679         20.42 +/- 0.04\n\nThe magnitude in the table is not corrected for the Galactic extinction\ndue to the reddening of E(B-V) = 0.032 in the direction of the burst\n(Schlegel et al. 1998).\n\nThere is no convincing evidence for UVOT variability of the source.\n\nFurther Swift observations are planned to determine whether the source\nis fading.",
  "circularId": 13709,
  "createdOn": 1346438594000,
  "email": "wayne@milkyway.gsfc.nasa.gov",
  "subject": "GRB 120830A: Swift-XRT and UVOT observations",
  "submitter": "Wayne Baumgartner at GSFC  <wayne@milkyway.gsfc.nasa.gov>",
  "eventId": "GRB 120830A"
}