TITLE: GCN CIRCULAR NUMBER: 10043 SUBJECT: GRB 091018: BOOTES-3 observations DATE: 09/10/19 19:49:59 GMT FROM: Antonio Deugarte at IAA-CSIC A. de Ugarte Postigo (INAF-OAB), P. Kubanek (U. Valencia, IAA-CSIC), M. Jelinek, A.J. Castro-Tirado, J. Gorosabel, R. Cunniffe, S. Guziy (IAA-CSIC), B.A. Allen (Vintage Lane Obs.) and P. Yock (Auckland Univ.) report: We have observed the afterglow of GRB 091018 (Stamatikos et al. CGN 10034) with the 0.6m Yock-Allen telescope (BOOTES-3) located in Blenheim (New Zealand). A combination of 21x30s unfiltered images with mean epoch Oct. 19.625 UT (18.2 hours after the burst) shows the afterglow at a magnitude of R=20.0+/-0.3. The photometry has been obtained using as comparison 5 USNO-B1.0 stars. This magnitude implies a rough decay slope of alpha = 0.7 +/- 0.2 (with F ~ t^(-alpha)) as compared to the values of Filgas et al. (GCN 10039). Further analysis is ongoing.