GCN Circular 33734
Subject
GRB 230506C: TSHAO possible afterglow candidate
Date
2023-05-06T23:13:08Z (a year ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
N. Pankov (HSE), I. Reva (FAI), A. Pozanenko (IKI), S. Belkin (IKI) report on behalf of GRB-IKI-FuN:
We observed the field of GRB 230506C detected by Swift (Tohuvavohu et al., GCN 33731) with Zeiss-1000 telescope of Tien Shan Astronomical Observatory stating on May, 06 (UT) 17:24:54 in R-filter.
Within Swift-BAT error circle (Tohuvavohu et al., GCN 33731) we detected uncatalogued object in coordinates of (J2000) 08:57:28.13 +45:07:59.48 with uncertainties of 0.3 arcsec in each coordinate. The object is absent in SDSS images. A distance of the object from the center of BAT error circle is ~30 arces. Preliminary photometry of a stacked images is following
Date UT start t-T0 Filter Exp. OT Err. UL(3 sigma)
(mid, days) (s)
2023-05-06 17:24:54 0.02914 R 23*120 20.1 0.1 21.5
The photometry is based on nearby USNO-B1.0 stars.
We suggest that the object is a candidate for the afterglow of GRB 230506C.