It was observed for only one month between February 13 and March 12
in 1977. It has not been observed since that.
The condition was worst at the discovery, at conjunction with the sun
around the perihelion passage. It has been returning in better
condition than at the discovery every time since that, but not been
observed.
Kazuo Kinoshita's calculation revealed that it passed close by Jupiter
in 1973, then the perihelion distance dramatically decreased from 5.9
A.U. down to 2.8 A.U. Probably it was in outburst in 1977 because it
came closer to the sun for the first time.
It was not observed in 1999, so the usual brightness must be fainter
than at the discovery by 3 mag or more. It must be fainter than 20 mag
usually.
Kazuo Kinoshita's calculation reveals that it will pass close by
Jupiter in 2055 again, then the perihelion distance increases up to
3.8 A.U. As a result, it will be apparently fainter furthermore by 3
mag, and it will never be brighter than 23 mag.