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  <yuanfang@umich.edu>

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