TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  1480
SUBJECT: Early Time Limits for GRB020813
DATE:    02/08/13 22:29:44 GMT
FROM:    Eli Rykoff at Univ. of Michigan/ROTSE  <erykoff@umich.edu>

E. Rykoff, D. Smith on behalf of the ROTSE Collaboration, report:

"ROTSE-IIIa responded automatically to GRB020813 (HETE trigger 2262) and started 
imaging at 13 August 2002 02:48:48.50 UT, 4.48 minutes after the start of the 
burst, and 15 seconds after receipt of GRB coordinates from the GCN. This 
response was during early twilight at Los Alamos National Laboratory, and our 
first several images were saturated by bright sky. Our first usable exposure, 60 
seconds in duration beginning at 03:02:36.28, shows no optical transient to an 
unfiltered limiting magnitude ~ 16.0 under adverse conditions. Our typical limit 
is several magnitudes deeper. This limit is around 0.5 magnitude brighter than 
the extrapolation of the decay of the OT as reported by Li, et. al. (GCN 
circular 1473)."

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