XRF 020427 was an X-ray flash. It was observed with the Hubble Space Telescope (HST) on the 10th of June 2002 in rather poor seeing conditions. The afterglow of this XRF resembles the properties of some gamma-ray bursts (GRB). This is probably due to an inefficient shock from XRF 020427. This further strengthens the connection of X-ray burst to GRBs.
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