TITLE: GCN CIRCULAR NUMBER: 16309 SUBJECT: GRB 140518A: T100 observations DATE: 14/05/19 16:13:14 GMT FROM: Eda Sonbas at NASA/GSFC E. Sonbas (Adiyaman Univ.), T. Guver (Istanbul Univ.), U. Temiz, F.Dolek (Cukurova Univ.), E. Gogus (Sabanci Univ.), O. Erece (Akdeniz Univ.), O. Basturk (Ankara Univ.) report on behalf of a larger collaboration We observed the field of Swift GRB 140518A (Melandri et al., GCN#16298) with the 1.0 meter T100 telescope (Bakirlitepe, TUBITAK National Observatory, Turkey), starting May, 18, 21:35:41 UT (~ 12.3 hours after the trigger). 5 x 300 s exposures were obtained in the R filter under moderate weather conditions. We do not detect an optical afterglow within the reported XRT error circle down to a limiting magnitude of >20.37 (2-sigma) in the combined R band image. We are grateful to TUBITAK National Observatory for prompt scheduling the observations and technical support.