[vsnet-grb-info 27496] GRB 210306A: iTelescope optical afterglow observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  29599
SUBJECT: GRB 210306A: iTelescope optical afterglow observations
DATE:    21/03/06 05:53:48 GMT
FROM:    Filipp Dmitrievich Romanov at Amateur astronomer  <filipp.romanov.27.04.1997 at gmail.com>

I observed the field of GRB 210306A (D'Elia et al., GCN Circ. 29597)
with remote telescope T24 (0.61-m f/6.5 reflector + CCD) of
iTelescope.Net in Sierra Remote Observatory (Auberry, California, USA)
on 2021-03-06. Two images (exposures 300 seconds, BINx1) were obtained
with luminance filter since 04:42:56 UT (2939 seconds after the
trigger) and since 04:48:59 UT (3302 seconds after the trigger). I
clearly detected the optical afterglow in UVOT position. The following
magnitudes were measured from comparison to r magnitudes of nearby
stars from Pan-STARRS DR1 catalogue (Chambers et al., 2016): 17.80
(+/- 0.057) and 17.97 (+/- 0.038).

Magnitudes were not corrected for Galactic extinction.

Stacked image available here:
https://www.flickr.com/photos/filipp-romanov/51007330278