2 Data

The 4B GRB catalog available at the www (Paciesas et al. 1998) has been used as the source of GRBs parameters and positions. This database has been cross-correlated with the list of supernovae compiled by us over the whole time interval of the 4B catalog from reports published in the IAUC. Since the OA are known to peak roughly one day after the corresponding GRB and then declining gradually, and since the first SN observations are usually delayed after their maxima, we have searched for correlations between GRBs and supernovae detected within the particular GRB error boxes up to 30 days after the gamma ray events (for a more complex approach including searches for SNe detected before GRB triggers see Hudec et al. 1999).

Altogether 2133 GRBs (BATSE triggers 105 to 6720) and 613 SN detected between April 21, 1991 and May 3, 1998 have been analyzed.