TITLE: GCN CIRCULAR NUMBER: 23416 SUBJECT: GRB 181110A: optical observations from iTelescope SSO DATE: 18/11/10 12:45:01 GMT FROM: Denis Denisenko at SAI MSU D. Denisenko (SAI MSU), M. Gnetov, E. Guskov, M. Orlova, V. Smirnov, I. Vodolazskiy, N. Zlobin, D. Fernandez Ortiz (Center on Donskaya, Moscow) report: GRB 181110A: optical observations from iTelescope SSO The field of bright long GRB 181110A (Evans et al., GCN Circ. 23413) was observed remotely from Siding Spring using iTelescope.Net T17 instrument (0.43-m f/6.8 reflector + FLI PL4710 CCD) on 09:49-09:55 UT. Four unfiltered 60-sec exposures were obtained, until the telescope was occupied by the other scheduled user. The optical transient is well detected on 4 images and slowly fading, in accordance with Yamanaka et al., GCN Circ. 23414. The following magnitudes were measured using the nearby star USNO-B1.0 0531-0876625 as a reference with R2=14.80 in USNO-B1.0: TIME-OBS, JD T-T0,s Mag. Error ------------------------------- 2458432.9093 3952 15.60 0.02 2458432.9105 4055 15.64 0.01 2458432.9117 4156 15.68 0.01 2458432.9128 4257 15.77 0.02 ------------------------------- Comparison of T17 iTelescope.Net image and 1990-09-19 DSS Red plate is uploaded to http://scan.sai.msu.ru/~denis/GRB/GRB181110A-T17-DSS-anim.gif (FOV 5'x5', 2x zoom).