My observations of Hyakutake show a bright, very small (but definitely NOT point-like) feature in the center of the comet. It is tempting to think that that is the nucleus of the comet. But the image seems much too large for that. The comet's nucleus is probably just a few kilometers in diameter. Any light reflected from such a tiny source should appear as a point. And I would have thought it would be very faint, too, since the nucleus is so small. Nor does it seem to me that I'm seeing just the brightest part of the coma: The "nucleus" seems to be distinct, much brighter than the immediately adjacent inner parts of the coma.