Scientific Seminars

Discovery of Naked-Eye Burst variable prompt optical emission and perspectives of wide-field monitoring for fast optical transients

G.Beskin on behalf of TORTORA team

2009-03-03    14:00    IASF - Sala riunioni

We discuss the strategy of search for fast optical transients accompanying gamma-ray bursts by means of continuous monitoring of wide sky fields. We describe the equipment we create for such a task, able to detect optical flashes brighter than 10-11 mag with 0.13s temporal resolution, as well as corresponding software and data processing methods. As an achievement of our program we present the results of high temporal resolution observations of prompt optical emission which accompanied the Naked-Eye Burst, GRB083019B, by TORTORA fast wide-field camera placed at Italian REM telescope at La-Silla, Chile. We were able to study the location of this event before, during and after the burst itself, and acquired its complete optical light curve with unprecedented level of details. The light curve shows four nearly equidistant (~9 seconds separation) peaks, as well as a signature of one-second periodic intensity variations during the last peak. We present the results of comparison of optical data with those acquired by gamma-ray satellites, as well as its possible theoretical implications. Also we discuss the perspectives of this strategy and possible design of next-generation equipment for wide-field monitoring which will be able to detect optical transients and to study their color and polarization properties with high time resolution