TITLE: GCN CIRCULAR NUMBER: 16264 SUBJECT: GRB 140423A: AAO optical upper limits DATE: 14/05/14 14:27:00 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Volnova (IKI), R. Inasaridze (AAO), O. Kvaratskhelia (AAO), V. Ayvazian (AAO), Yu. Krugly (IA KhNU), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the optical afterglow (Elenin et al., GCN 16143; Kaur et al., GCN 16144; Ferrante et al., GCN 16145; Chester et al., GCN 16147; Maehara et al., GCN 16151) of the Swift GRB 140423A (Sonbas et al., GCN 16142) with AS-32 (0.7m) telescope of Abastumani Observatory on Apr. 24 at (UT) 00:29-01:16 and Apr. 24 (UT) 17:46-19:16. We obtained several unfiltered frames with exposures of 120 s. Within the enhanced XRT circle (Beardmore et al., GCN 16155) in the stacked images from both epochs we do not detect the afterglow. The details of the photometry are the following: UT start t-T0 Filter Exp. Uplim (mid, days) (s) (3 sigma) 00:29:23 0.68139 None 16*120 20.3 The photometry is based on SDSS stars, R mag (R mag obtained using ugriz transformations in BVRI (Lupton, 2005): SDSS id R_Lupton J130858.37+494547.9 15.418 ± 0.018 J130914.51+494636.5 18.661 ± 0.019