Home Page       Sat Aug 16 13:20:21 JST 1997

Observations before discovery

In many cases of bright comets, after the announcement of the discovery, some checks old pictures and find out the elder images of the comet. For example, comet Hyakutake was detected in a picture taken about one month before the discovery. Comet Hale-Bopp was retrospective discovered in a picture taken about two months before, and even in a CCD image taken more than two years before.