{
  "bibcode": "2022GCN.32664....1R",
  "body": "I observed the optical afterglow of the extremely bright GRB 221009A =\nSwift J1913.1+1946 (Dichiara et al., GCN Circ. 32632) remotely using\n0.61-m f/6.5 Corrected Dall-Kirkham telescope of Burke-Gaffney\nObservatory (Lane, 2018, RTSRE, 1, 119) on 2022-10-10. Twelve images\nwith exposures of 300 seconds and I�� filter were obtained, midtime of\nthe first image is 02:06:45 UTC (11h56m after the trigger), midtime of\nthe last image is 03:09:02 UTC (12h58m after the trigger).\n\nI clearly detected the afterglow and measured (aperture photometry,\nwithout deblending) following magnitudes of the afterglow from\ncomparison to transformed (from Lupton 2005 formula) magnitudes of\nnearby stars from the Pan-STARRS DR1 catalogue (Chambers et al.,\n2016):\n\nTime (UTC)//Ic magnitude//Error\n02:06:45  15.54  0.12\n02:12:20  15.60  0.10\n02:17:55  15.54  0.11\n02:23:29  15.60  0.11\n02:29:04  15.64  0.12\n02:34:38  15.59  0.11\n02:41:08  15.67  0.11\n02:46:43  15.69  0.10\n02:52:18  15.69  0.11\n02:57:53  15.64  0.12\n03:03:27  15.70  0.13\n03:09:02  15.92  0.13\n\nMagnitudes were not corrected for Galactic extinction.\n\nFITS files available here:\nhttps://observatory.smu.ca/~bgo/sm/id.php?app=0&id=20769 and\nhttps://observatory.smu.ca/~bgo/sm/id.php?app=0&id=20770\n\nStacked image: https://observatory.smu.ca/~bgo/research/GRB_221009A.jpg\n\nF. D. Romanov (AAVSO member, observer code: RFDA).",
  "circularId": 32664,
  "createdOn": 1665418911000,
  "email": "filipp.romanov.27.04.1997@gmail.com",
  "subject": "GRB 221009A (Swift J1913.1+1946): Burke-Gaffney Observatory optical observations",
  "submitter": "Filipp Dmitrievich Romanov at Amateur astronomer  <filipp.romanov.27.04.1997@gmail.com>",
  "eventId": "GRB 221009A"
}