Gamma-ray burst GRB 050724

On July 24, 2005, the NASA/PPARC/ASI Swift satellite detected another short gamma-ray burst, GRB 050724. Subsequent observations, including some with the ESO Very Large Telescope, allowed astronomers to precisely pinpoint the position of the object, lying about 13,000 light-years away from the centre of an elliptical galaxy that is located 3,000 million light-years away (redshift 0.258). (Left) VLT optical image taken on July 24, 12 hours after the burst, showing the position of the gamma-ray burst GRB 050724 as measured by the Swift X-Ray Telescope (XRT) and the Chandra X-ray satellite. The blue cross is the position of the optical afterglow. The burst positions are superimposed on a bright red galaxy at redshift z=0.258. (Right) Difference between two VLT images taken on July 24 and 29, clearly revealing the presence of the GRB.