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GCN Circular 33528

GRB 230328B: Mondy optical afterglow confirmation
2023-03-28T16:31:55Z (a year ago)
Alexei Pozanenko at IKI, Moscow <>
N. Pankov (HSE), E. Klunko (ISTP), A. Pozanenko (IKI), S. Belkin (IKI) 
report on behalf of GRB IKI FuN:

We observed  the field of Swift GRB 230328B (Gropp et al. GCN 33527) 
with AZT-33IK telescope of Mondy observatory  in  R-filter on
2023-03-28 starting (UT) 15:27:18. We clearly detect the optical 
afterglow of GRB 230328B (Gropp et al. GCN 33527) at the position of 
(J2000) 19 24 01.828 +80 00 34.53 with an error of 0.5 arcsec in both 
coordinates, which coincides with the position of UVOT (Gropp et al. GCN 

Preliminary photometry  of a stack of the first 5 images is following

Date       UT start  t-T0     Exp.  Filter   OT     Err.  UL(3sigma)
                    (mid, days)  (s)

2023-03-28  15:27:18   0.026047 5*60 R        18.9  0.2   21.1

The photometry is based on nearby USNO-B1.0 stars.
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