GCN Circular 30404
N. Pankov (IKI, HSE), S. Nazarov (CrAO), R. Ya. Inasaridze (AbAO), A. Pozanenko (IKI), S. Belkin (IKI, HSE) report on behalf of IKI GRB FuN: We observed the filed of Swift/BAT-GUANO detection GRB 210706A (Tohuvavohu et al., GCN 30393), GRB 210706A also triggered Konus-Wind (Ridnaia et al., GCN 30403) with Sintesz-Newton 350mm f/5 telescope of CrAO observatory and AS-32 telescope of Abastumani observatory (AbAO). Observation started on 2021-07-06 (UT) 22:52:40 and consist of 6 images of 300 s exposure in Clear filter (Sintesz-Newton) and in R-filter (UT) 2021-07-06 (UT) 20:23:40 (AS-32). In bothe telescopes we cover the whole localization region of Swift/BAT-GUANO (Tohuvavohu et al., GCN 30393). We find no new optical sources in either of the two XRT candidates (https://www.swift.ac.uk/ToO_GRBs/00021455/). In particular no source was detected in XRT afterglow candidate #2 (Tohuvavohu et al., GCN 30399). Upper limit for of the stacked image is following Date UT start t-T0 Filter Exp. OT err UL(3) Telescope (mid, days) (s) 2021-07-06 20:23:40 0.50719 R 9*60 n/d n/d 20.5 AS-32 2021-07-06 22:52:40 0.60755 Clear 6*300 n/d n/d 21.5 Newton The photometry is based on nearby USNO-B1.0 (R2) stars. Our non-detections is consistent with results of GROWTH-India Telescope (Kumar et al., GCN 30402).