Kazuo Kinoshita's calculation revealed that it approached to Jupiter
down to 0.15 A.U. in 1987, and the perihelion distance was reduced
from 3.4 A.U. down to 2.0 A.U. Then the comet comes to be bright, and
it was discovered.
The light curves are very different among every apparition, maybe
because it has just come to the inner Solar System. The brightness at
the perihelion passage differs by about 4 mag between 1996 and 2003.