{
  "bibcode": "2007GCN..6639....1Z",
  "body": "H. Ziaeepour (UCL-MSSL), S. D. Barthelmy (GSFC),\nA. P. Beardmore (U Leicester), D. N. Burrows (PSU),\nP. A. Evans (U Leicester), K. L. Page (U Leicester) and\nE. Troja (INAF-IASFPA) report on behalf of the Swift Team:\n\nAt 10:00:56 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 070721 (trigger=285653).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 3.176, -28.546 (J2000) with an uncertainty of 3 arcmin\n(radius, 90% containment, including systematic uncertainty). \nWe have very little further information at this time (lightcurve, etc)\nbecause there appears to be a problem with the messages. \n\nThe spacecraft slewed promptly and the XRT found a source\nat location \nRA(J2000) = 3.16355 degrees, \nDec(J2000) = -28.54928 degrees, \nwhich is 40 arcseconds from the BAT position. We do not have\nan  error estimate, but the typical uncertainty for on-board centroids\nis 6 arcseconds. The source flux was about 3.25e-10 cgs. At this point\nwe do not have enough data to be able to  tell whether this source is\nfading. We note that there is a bright 2MASS object at this position: \n2MASS 00123943-2832566 (2.5 arcseconds from the XRT position). \nWe are waiting for processing of  the downlinked Malindi data\nfor more details. \n\nAt this moment no UVOT data are available. We are waiting for the \nnext Malindi pass to download more data. \n\nWe note that while writing this Circular, Swift slewed to the next\ntrigger following this one. This is unusual and raises the\npossibility that this burst is not real. We will not be certain until\nthe Malindi data can be analyzed. \n\nBurst Advocate for this burst is H. Ziaeepour (hz AT mssl.ucl.ac.uk). \nPlease contact the BA by email if you require additional information\nregarding Swift followup of this burst. In extremely urgent cases, after\ntrying the Burst Advocate, you can contact the Swift PI by phone (see\nSwift TOO web site for information: http://www.swift.psu.edu/too.html.)\n\n[GCN OPS NOTE(24aug07): Per author's request, the trigger time was corrected\nfrom 10:01:08 to 10:00:56. Acknowledgements to F. Marshall.]",
  "circularId": 6639,
  "createdOn": 1185015542000,
  "email": "scott@lheamail.gsfc.nasa.gov",
  "subject": "GRB 070721: Swift detection of a possible burst",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>",
  "eventId": "GRB 070721"
}