GRB 221009A (Swift J1913.1+1946): Burke-Gaffney Observatory optical observations

I observed the optical afterglow of the extremely bright GRB 221009A = Swift J1913.1+1946 (Dichiara et al., GCN Circ. 32632) remotely using 0.61-m f/6.5 Corrected Dall-Kirkham telescope of Burke-Gaffney Observatory (Lane, 2018, RTSRE, 1, 119) on 2022-10-10. Twelve images with exposures of 300 seconds and I<D1><81> filter were obtained, midtime of the first image is 02:06:45 UTC (11h56m after the trigger), midtime of the last image is 03:09:02 UTC (12h58m after the trigger). I clearly detected the afterglow and measured (aperture photometry, without deblending) following magnitudes of the afterglow from comparison to transformed (from Lupton 2005 formula) magnitudes of nearby stars from the Pan-STARRS DR1 catalogue (Chambers et al., 2016): Time (UTC)//Ic magnitude//Error 02:06:45 15.54 0.12 02:12:20 15.60 0.10 02:17:55 15.54 0.11 02:23:29 15.60 0.11 02:29:04 15.64 0.12 02:34:38 15.59 0.11 02:41:08 15.67 0.11 02:46:43 15.69 0.10 02:52:18 15.69 0.11 02:57:53 15.64 0.12 03:03:27 15.70 0.13 03:09:02 15.92 0.13 Magnitudes were not corrected for Galactic extinction. FITS files available here: https://observatory.smu.ca/~bgo/sm/id.php?app=0&id=20769 and https://observatory.smu.ca/~bgo/sm/id.php?app=0&id=20770 Stacked image: https://observatory.smu.ca/~bgo/research/GRB_221009A.jpg F. D. Romanov (AAVSO member, observer code: RFDA).