Kazuo Kinoshita's calculation revealed that it passes close by Jupiter
frequently, and it has been getting closer to the sun gradually. The
perihelion distance was 1.5 A.U. at the discovery in 1979, then
reduces down to 1.4 A.U. in 1998, 1.2 A.U. in 2015, 1.1 A.U. in 2022
and 0.98 A.U. in 2033.
While getting closer to the sun, it must be observable brighter on and
on theoretically. But actually, the brightness of this comet is
unstable, completely different among every appearance.
It was very faint as 17 mag in 1979, however, it was very bright in
1991 and 1998. Then it became faint again in 2004.
An unusual outburst up to 9.5 mag was also observed in 1972.