TITLE: GCN CIRCULAR NUMBER: 5796 SUBJECT: GRB 061110: ROTSE-III Optical Limits DATE: 06/11/10 12:37:16 GMT FROM: Brad Schaefer at LSU B. E. Schaefer (Louisiana State), E.S. Rykoff (U Mich), F. Yuan (U Mich), W. Rujopakarn (U Arizona), report on behalf of the ROTSE collaboration: ROTSE-IIIa, located at Siding Spring Observatory, Australia, responded to GRB 061110A (Swift trigger 238108), producing images beginning 8.8 s after the GCN notice time. An automated response took the first image at 11:48:04.9 UT, 43.6 s after the burst, under fair conditions. We took 10 5-sec, 10 20-sec and 10 60-sec eposures. These unfiltered images are calibrated relative to USNO A2.0 (R). Comparison to the DSS (second epoch) reveals no new sources within the 3-sigma BAT error circle and also within the XRT error circle, for both single images and coadding into sets of 10; the field is not crowded. Individual images have limiting magnitudes ranging from 14.3-17.1; we set the following specific limits. start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd? -------------------------------------------------------------------- 11:48:04.9 11:48:09.9 5 16.2 43.6 N 12:07:54.0 12:17:13.9 559 17.5 1232.7 Y