Rapid optical follow-up observations of SGR events with ROTSE-I

The primary mission of the Robotic Optical Transient Search Experiment (ROTSE) is to search for contemporaneous optical emission from GRBs. Among the triggers ROTSE receives via the GRB Coordinates Network (GCN), there are a number from Soft-Gamma Repeater (SGR) events. Since beginning operations in March 1998, ROTSE-I has triggered on 16 observable SGR events. Ten of these events had useful data, eight events from SGR 1900+14 and two events from SGR 1806−20. The error regions for these SGRs are a small fraction of the ROTSE 16°×16° field of view and have been searched for new or variable objects. Limits on optical transient counterparts are in the range mROTSE≈12.5–15.5 during the period 10 seconds to 1 hour after the observed SGR events.