[vsnet-grb-info 2643] GRB 060111: ROTSE-III Optical Limits

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4480
SUBJECT: GRB 060111: ROTSE-III Optical Limits 
DATE:    06/01/11 05:12:43 GMT
FROM:    Fang Yuan at ROTSE  <yuanfang at umich.edu>

F. Yuan (U Mich), W. Rujopakarn (U Mich), E.S. Rykoff (U Mich), S.A. 
Yost (U Mich), report on behalf of the ROTSE collaboration:

ROTSE-IIId, located at the Turkish National Observatory at Bakirlitepe, 
Turkey, responded to GRB 060111 (Swift trigger 176818), producing images 
beginning 5 s after the GCN notice time. An automated response took the 
first image at 04:23:23.2 UT, 17.1 s after the burst, under twilight 
conditions. We took 10 5-sec eposures before the individual images were 
saturated due to twilight. 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 and particularly at the XRT position, for both 
single images and coadding into sets of 10. Individual images have 
limiting magnitudes ranging from 13.4-13.8; we set the following 
specific limits.

start UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd?
--------------------------------------------------------------------
04:23:23.2   04:23:28.2         5     13.4           17.1       N
04:23:23.2   04:25:31.0     127.8     14.5           17.1       Y