New periodic comet discovered in 2004.
The eccentricity is small as 0.29. The brightening and fading is slow
along a 7.5 log r formula. Therefore, it is bright as 18 mag even
around the aphelion, and it is observable all through the orbit.
Kazuo Kinoshita's calculation revealed that it approached to Jupiter
in 2001 July, and the perihelion distance was reduced from 3.8 A.U
down to 2.9 A.U. However, Kinoshita's calculation also revealed that
it will approach to Jupiter in 2024 July again, and the perihelion
distance will be increased again up to 3.5 A.U. The comet comes closer
to the Sun in only three apparitions, 2005, 2013 and 2021, during
recent 200 years.
Based on the current brightness, the comet must have been about 18 mag
at the aphelion, and must have been bright as 16 mag at the perihelion
before 2001. But actually, it was not discovered until 2004. It
suggests that the comet became active by coming closer to the Sun.
The maximum brightness around the perihelion will fade down to 16 mag
after 2024. But it may be much fainter if the current activity settles