TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4523
SUBJECT: GRB 060116: ROTSE-III Optical Limits
DATE:    06/01/16 15:12:28 GMT
FROM:    Eli Rykoff at U of Michigan/ROTSE  <erykoff@umich.edu>

E.S. Rykoff (U Mich), S.A. Yost (U Mich), H. Swan (U Mich), report on 
behalf of the ROTSE collaboration:

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 
060116 (Swift trigger 177533, Campana, et al, GCN 4519), producing 
images beginning 9.0 s after the GCN notice time. An automated response 
took the first image at 08:38:46.0 UT, 78.8 s after the burst, under 
fair conditions. We took 10 5-sec, 10 20-sec and 70 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, or in the XRT error circle (Campana, et al, 
GCN 4522) for both single images and coadding into sets of 10. 
Individual images have limiting magnitudes ranging from 15.6-16.9; we 
set the following specific limits.

start UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd?
--------------------------------------------------------------------
08:38:46.0   08:38:51.0         5     16.1           78.8       N
08:38:46.0   08:39:55.0        69     17.7           78.8       Y
08:40:07.6   08:44:50.7       283     18.0          160.4       Y