GRB 020409, 2nd /session define format EPOCH1 = optical observations. Stecklum, B. ; Zeh, A. ; Klose, S. ; Hartmann, D. H. ; Leising, M. ; Henden, A. A. ; Vrba, F. J. ; Greiner, J. Abstract Publication: GRB Coordinates Network Pub Date: 2002 Bibcode: 2002GCN..1364....1S