TITLE:   GCN CIRCULAR
NUMBER:  32487
SUBJECT: GRB 220826A: iTelescope optical afterglow observations
DATE:    22/08/26 17:55:46 GMT
FROM:    Filipp Dmitrievich Romanov at Amateur astronomer  <filipp.romanov.27.04.1997@gmail.com>

I observed the field of GRB 220826A (Caputo et al., GCN Circ. 32484)
using remote telescope T59 (0.51-m f/6.8 reflector + CCD) of
iTelescope.Net in Siding Spring Observatory (Australia) on 2022-08-26.
Three images were obtained from 12:16:07 UTC (1246 sec. after the
trigger) with a Luminance filter (300 seconds exposures, BINx1), but
in the third of them, the object is already below the minimum target
elevation for the telescope.

I clearly detected (SNR ~ 8 in the stacked image) the optical
afterglow with UVOT position and measured its magnitude = 19.3 +/- 0.2
in the stacked image (midtime = 12:23:09 UTC means 1668 sec. after the
trigger), airmass was from 4.041 to 4.463. I compared with Sloan r'
magnitudes of nearby stars from APASS DR9 catalogue (Henden et al.,
2016).

Magnitude was not corrected for Galactic extinction.

Stacked image available here:
https://www.flickr.com/photos/filipp-romanov/52313060415