{
  "bibcode": "2002GCN..1696....1S",
  "body": "L. Strolger, J. E. Rhoads, A. Fruchter, I. Burud (STScI); A. J. Levan\n(Leicester), and J. J. Kavelaars (McMaster) report.\n\nIn follow-up to our observations reported in GCN 1684, additional\nobservations of the GRB 021112 error box (GCN 1682) were made using the\nKPNO-4m + Mosaic I imager on UT 2002 November 13.2. Four R-band images\nwere obtained dithered to cover the entire HETE-2 error circle, for a\ncombined exposure time of 1680s. Further detailed analysis of the\nfield, including localized registration, PSF-matching, and subtraction\nof the combined observations made Nov. 12.3 from the combined\nobservations made Nov. 13.2 have revealed a candidate optical transient\n(OT) located just outside the HETE-2 90% error circle, at\n\tRA: 02:38:27.80 Dec: +48:33:18.4 (J2000.0)\nCoordinates and offsets from neighboring stars were determined from\ndirect comparison to the DDS-2 (R-band). A source is visible at the\nlimit of the DDS-2 red plate at the position of the variable object.\n\nPSF photometry performed on the candidate OT and 5 neighboring stars have\nshown the object apparently brightened by 0.55 +/- 0.03 magnitudes between\nthe observations made on Nov. 12.3 and Nov 13.2.\nFurther information summarizing the discovery and analysis\ncan be found on http://www.stsci.edu/~fruchter/GRB/021112/ .\n\nAn approximate photometric zero point (based only on the typical throughput\nfor the camera) gives R=21.1 on Nov 12.3 and R=20.6 on Nov. 13.2.\nLocal reference star magnitudes are given on the above web page to\nfacilitate comparison with other data.",
  "circularId": 1696,
  "createdOn": 1037659768000,
  "email": "rhoads@stsci.edu",
  "subject": "GRB 021112: Variable Source in R-band search",
  "submitter": "James Rhoads at STScI  <rhoads@stsci.edu>",
  "eventId": "GRB 021112"
}