{
  "bibcode": "2021GCN.30305....1R",
  "body": "Filipp D. Romanov (Russia) and David J. Lane (Saint Mary's University,\nCanada) report:\n\nFilipp Romanov observed optical afterglow of GRB 210619B (D'Avanzo et\nal., GCN Circ. 30261) remotely using 0.355-m f/6.2 Schmidt-Cassegrain\ntelescope of Abbey Ridge Observatory (it is owned by Dave Lane) in\nCanada, on 2021-06-21.\n\nEight images (with exposures: 660, 840, 720, 840, 720, 720, 780 and\n720 seconds) were obtained with Cousins R filter from 02:29:26 to\n04:56:00 UTC. The optical afterglow (with UVOT position) is clearly\n(SNR = 11) visible in the stacked image (mid time = 03:42:42 UTC, that\nis 1.155 days after the trigger). Romanov measured its magnitude\ncomparing to transformed (using formula Rc=r���-0.22 from Dymock &\nMiles, 2009) r' magnitudes of nearby stars from Pan-STARRS DR1\ncatalogue (Chambers et al., 2016). The measured magnitude = 20.0 +/-\n0.2. Magnitude was not corrected for Galactic extinction.\n\nStacked image available here:\nhttp://www.abbeyridgeobservatory.ca/images/GRB210619B.jpg",
  "circularId": 30305,
  "createdOn": 1624381239000,
  "email": "filipp.romanov.27.04.1997@gmail.com",
  "subject": "GRB 210619B: Abbey Ridge Observatory optical afterglow observation",
  "submitter": "Filipp Dmitrievich Romanov at Amateur astronomer  <filipp.romanov.27.04.1997@gmail.com>",
  "eventId": "GRB 210619B"
}