{
  "bibcode": "2010GCN.10909....1L",
  "body": "A.J. Levan (U. Warwick), N.R. Tanvir, K. Wiersema (U. Leicester),\nS.B. Cenko (UC Berkeley) report on behalf of a larger collaboration:\n\n\"We obtained two epochs of observations of GRB 100628A (Immler et\nal. GCN 10895) with Gemini-North. The first was obtained starting\nat 28 Jun, 08:59 UT, approximately 43 minutes after the burst, with\na second obtained on 29 Jun 05:50 UT, ~21.5 hours after the burst.\nA total of 1200s of exposure time were obtained in the i-band. Our\nimages covers ~90% of the BAT refined error circle (Barthelmy et\nal GCN 10896), including the position of the candidate X-ray afterglow\nidentified by Starling et al. (GCN 10899; 10907).\n\nDigital image subtraction performed between the two epochs does not\nreveal any candidate variable sources between the two epochs, to\nan approximate limiting magnitude of i~24. In particular, we do not\nfind any evidence for variability in any of the galaxies identified\nby Berger et al. (GCN 10902) surrounding the XRT location,\nincluding G1, which now lies within the XRT error circle\n(Starling et al. GCN 10907; Berger et al. GCN 10908)\n\nWe also note the presence of two, apparently point like sources\nlying within the refined XRT error circle, at locations of\n\nS1:\nRA(J2000) 15:03:53.45\nDEC(J2000) -31:39:54.2\n\nS2:\nRA(J2000)  15:03:53.73\nDEC(J2000) -31:39:48.4\n\nBoth are unresolved at the resolution of our observations, but\nneither show apparent variability between the two epochs.\n\nAn image, showing the field as observed by Gemini-North can be found\nat\n\nhttp://www.star.le.ac.uk/~anl/100628A\n\nWe thank the staff of Gemini-North for their assistance with these\nobservations.\"",
  "circularId": 10909,
  "createdOn": 1277833597000,
  "email": "A.J.Levan@warwick.ac.uk",
  "subject": "GRB 100628A: Gemini North Observations",
  "submitter": "Andrew Levan at U.of Leicester  <A.J.Levan@warwick.ac.uk>",
  "eventId": "GRB 100628A"
}