[vsnet-grb-info 27062] GRB 201223A: iTelescope optical afterglow observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  29165
SUBJECT: GRB 201223A: iTelescope optical afterglow observations
DATE:    20/12/24 02:49:44 GMT
FROM:    Filipp Dmitrievich Romanov at Amateur astronomer  <filipp.romanov.27.04.1997 at gmail.com>

I observed the field of GRB 201223A (Gropp et al., GCN Circ. 29158)
with remote telescope T18 (0.32-m f/8.0 reflector + CCD) of
iTelescope.Net in observatory AstroCamp at Nerpio (Spain) on
2020-12-23 since 19:49:22 UT (1 hour 50 minutes 56 seconds after the
trigger). 5 images (with exposures 300, 120 and 180 seconds) were
obtained with Astrodon luminance filter and 4 images (exposures: 300
and 60 seconds) with photometric Johnson V filter. I detected the
optical afterglow in images with position: RA 08:51:09.46 Dec
+71:10:47.00. It is not present in the Pan-STARRS images.

The following magnitudes were measured from comparison to r magnitudes
of nearby stars from Pan-STARRS DR1 catalogue (Chambers et al., 2016):

Time of start (UT)  Exp.time (s.)  Bin.  Mag. r   Mag. error    Filter
---------------------------------------------------------------------------
19:49:22            300            1     19.2     0.2           Luminance
19:56:25            300            1     19.3     0.4           V
20:26:25            300            2     19.9     0.4           V
20:33:07            300            2     20.1     0.3           Luminance
---------------------------------------------------------------------------

Magnitudes were not corrected for Galactic extinction.

Stacked image (4x300 + 2x120 + 180 sec.) available here:
https://www.flickr.com/photos/filipp-romanov/50753199496