1 Introduction

Despite exciting new results (7 GRB-related optical afterglows (OAs) discovered), there still remain questions: more than one fading optical object has been revealed in or close to GRB boxes in several cases and, in one case, more than one X-ray fading source has been found in GRB box. For GRB 970616, two X-ray fading counterparts and two optically fading objects, one inside gamma ray box but both outside X-ray boxes have been detected (Greiner et al. 1997). For GRB 970402, an optically variable/fading source was found outside the X-ray error box. The gamma-ray error box of GRB 970508 exhibits several optical variable sources, only one in the X-ray box (Djorgovski et al. 1997). There are two X-ray sources in the GRB 980425 error box. The fading X-ray source is not coinciding with optical and radio source (SN 1998bw). The obvious conclusion may be drawn, namely that not all optical and probably also not all X-ray variable/fading objects found at or close to the GRB positions are related to GRBs in question. There is a background of variable optical (and also X-ray ) sources not related to GRBs. This background is especially important for large error boxes.

Let us try to summarize what have we learned from the Optical Afterglows (OA) analyses: (1) 7 OAs were detected from 19 GRBs studied i.e. $\sim$40% of GRBs exhibit optical emission (2) they peak at 18-23 mag (3) they exhibit power law declines with mean power of - 1.2 (4) they seem to be related to faint host galaxies (but not all) (5) not all GRBs have an OA (6) the optical emission less than 3 hrs after GRBs remains poorly investigated (7) the direct optical emission is below V=7-10 mag (Hudec et al. 1999) (8) at least some OAs are very likely associated with GRBs e.g. due to excellent positional and temporal coincidence and common power law fading.

One can conclude that GRBs may be monitored and studied by observing their OAs. This may open a new observing window for monitoring GRBs. Further, the rate of OAs may be higher than the rate of GRBs due to different beaming, the factor is unknown but may be up to 100, hence such studies require good knowledge of OT related background (false events not related to GRBs but with similar transient behavior)