TITLE: GCN CIRCULAR NUMBER: 5919 SUBJECT: GRB 061214(?): ROTSE-III Optical Limits DATE: 06/12/14 13:07:05 GMT FROM: Fang Yuan at ROTSE F. Yuan (U Mich), B. E. Schaefer (Louisiana State), T. Guver (U Istanbul), D.A. Smith (Guilford) report on behalf of the ROTSE collaboration: ROTSE-IIIa, located at Siding Spring Observatory, Australia, responded to the possible burst GRB 061214 (Swift trigger 250908), producing images beginning 7.0 s after the GCN notice time. An automated response took the first image at 12:17:12.1 UT, 18.7 s after the burst, under fair conditions. We took 10 5-sec, 10 20-sec and 20 60-sec exposures. 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 error circle, for both single images and coadding into sets of 10. Individual images have limiting magnitudes ranging from 14.9-16.8; we set the following specific limits. start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd? -------------------------------------------------------------------- 12:17:12.1 12:19:32.0 139 17.1 18.7 Y 12:19:40.7 12:24:31.2 290 17.5 167.3 Y