Identification and Early Spectroscopic Observations
At 22:42:27 UT 26/07/09, the Burst Alert Telescope (BAT) on board of the SWIFT multi-wavelength space observatory triggered and located GRB 090726 gamma-ray burst event. A message about this burst was received by the observing researchers of the SAO RAS within minutes from its detection.
About half an hour after the BAT trigger, the first images were obtained
with the SAO RAS Zeiss-1000 telescope in four BVRI filters (see Fig.1).
A fading object of the R st.magn.18.26 missing in the DSS images was
detected within the initial SWIFT/XRT error circle of 3'. When the corrected
coordinates from the SWIFT/XRT X-ray telescope became available, they
coincided with our data.
Fig.2. The spectrum of the optical transient GRB090726 with identified lines, obtained with the BTA 1.54 hours after the burst.
Fig.1. Top: DSS image of the SWIFT/BAT error circle (R filter). Bottom: a direct image obtained with the SAO RAS Zeiss-1000 telescope 0.5 hours after the gamma-ray burst. The arrow points to the location of the optical transient GRB090726 (OT).