{
  "bibcode": "2007GCN..6002....1B",
  "body": "GRB 070107: Possible UVOT Afterglow\n\nP. T. Boyd (GSFC), M. Chester (PSU), C. B. Markwardt (CRESST/GSFC/USRA)\nand F. E. Marshall (GSFC) report on behalf of the Swift team:\n\nIn response to GRB 070107 (Stamatikos et al. GCN Circ. 5999)\nUVOT took a 100-s finding chart exposure with the White filter (160-650 nm)\nstarting 183 seconds after the BAT trigger, followed by a 400-s V\nfinding chart exposure. A second set of finding chart\nexposures was obtained starting 868s post-trigger. We detect a\nnew variable source inside the XRT error region (Kennea et al. \nGCN Circ. 6000) in the first exposure at\n\n  RA(J2000)  =  10 37 36.35\n  DEC(J2000) = -53 12 47.5\n\nwith a 1-sigma error radius of about 1 arcsec. However, we caution\nthat this source is in a crowded region at low galactic latitude, \nand only 4.1 arcsec from a bright V=15.9 cataloged star, which\ncauses the afterglow and the star to be blended in the UVOT image,\nand complicates the position, magnitude, and significance estimates.\nWe estimate a White magnitude of ~19.5 for the new source. The source\nis detected at a ~4-sigma significance level. The same source is\ndetected at a level of 2.7 sigma in the subsequent 400-s V finding chart. \nThe new source is not significant in later White and V exposures.\n\nWe note that the extinction estimate in this region (whose galactic \nlatitude is 4.56 degrees) is large, and uncertain.",
  "circularId": 6002,
  "createdOn": 1168286722000,
  "email": "padi@milkyway.gsfc.nasa.gov",
  "subject": "GRB 070107: Possible UVOT Afterglow",
  "submitter": "Padi Boyd at GSFC  <padi@milkyway.gsfc.nasa.gov>",
  "eventId": "GRB 070107"
}