Despite the recent instrumental developments, the photographic patrol data still represent the unique databases for real-time (simultaneous and pre-bursts) optical observations of GRBs. The recently operated alert systems can provide rapid follow up optical data (with time delays of order of tens of seconds) for less precisely localized CGRO BATSE triggers but their magnitude limits in this case are generally not substantially better (since they have to cover large FOVs) than those of photographic sky patrols and further, they will never be able to provide data for times before and during burst triggers. The improved sky patrols can yield valuable real-time and pre-burst optical data in the magnitude range 12-15.
Acknowledgements
The work has been supported by the Projects of the Czech Ministry for Education and Youth, Nos. ES02 and ES036.
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