TITLE: GCN CIRCULAR NUMBER: 16005 SUBJECT: GRB 140320B: ISON-NM optical observations DATE: 14/03/20 11:15:24 GMT FROM: Alexei Pozanenko at IKI, Moscow L. Elenin (KIAM), A. Volnova (IKI), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed of the field of the INTEGRAL GRB 140320B (Mereghetti et al., GCN 16004) with 0.4-m telescope of ISON-NM observatory starting on Mar., 20 (UT) 09:35:41. We took unfiltered images of 30 s exposures. We detect a fading optical afterglow of GRB 140320B (Guidorzi et al., GCN 16003) in a stacked image of total exposure 300 s and do not detect it in the next stacked image of the same exposure. Coordinates of the optical afterglow (J2000) 09 42 13.96 +60 16 05.9 (uncertainties of 1 arcsec) coincide with OT coordinates (Guidorzi et al., GCN 16003). Preliminary photometry of first stacked images is based on nearby USNO-B1.0 stars: UT mid, T0+ Filter Exposure, OT, err OT mid s 09:38:39 0.00878 none 10х30 19.1 0.2 09:44:40 0.03102 none 10х30 > 19.3 UpperlLimit