TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5366 SUBJECT: GRB 060729: ROTSE-III Detection of Optical Counterpart DATE: 06/07/29 20:49:33 GMT FROM: Robert Quimby at U of Texas/ROTSE R. Quimby (U Texas), H. Swan (U Mich), W. Rujopakarn (U Mich), and D.A. Smith (Guilford), report on behalf of the ROTSE collaboration: ROTSE-IIIa, located at the Siding Spring Observatory, Australia, responded to Swift trigger 221755 (GRB 060729; Grupe et al. GCN 5365). The first image was taken at 19:13:33.5 UT, 64.3 s after the burst (8.5 s after the GCN notice time). We detect a source coincident with the UVOT position (GCN 5365). In a 5-second image beginning at 19:14:02.1 and coincident with the second, larger peak in the BAT light curve, the object is approximately 15.5 magnitude (unfiltered; calibrated against the USNO A2.0), while a co-addition of our first 10 5-second images shows the object at approximately 16.6 magnitude. Images taken over the next 30 minutes do not show significant evolution, and have a mean magnitude of 16.5.