Hypothetical: Specific Rogue planet. When could be its discovery date given its orbital, size, and albedo parameters?

[PlutonianEmpire]

Hi all, I'm in need of a plausible detail for some of my fiction I write. I have a rogue planet with a set of orbital parameters as follows, looping around Sol:

Code: Select all

Orbit {
     Epoch 2458860.74038
     RefPlane "Ecliptic"
     PericenterDist 0.9
     Period 106.73035377261823
     Eccentricity 1.04
     Inclination 32.8
     AscendingNode 256.56103
     ArgOfPericenter 306.41318
}


So, the assumed SMA would be -22.5, with a Perihelion date of January 12, 2020.

Rogue Planet has two moons, with an external barycenter with the outer one, all with the following parameters:

Planet:
Radius 5469.6462 km
Mass 0.60543 M_earth
AlbedoBond 0.829
AlbedoGeom 0.935477

Inner Moon:
Radius 1326.212 km
Mass 0.005454 M_Earth
AlbedoBond 0.119
AlbedoGeom 0.1428
SemiMajorAxis 98304.460 km
Period 4.542 Days

Outer Moon:
Radius 2258.295 km
Mass 0.027646 M_earth
AlbedoBond 0.147
AlbedoGeom 0.1764
SemiMajorAxis 302025.266 km
Period 25.626

With that in mind, the Rogue Planet reaches apparent Magnitude 15 at 88 AU from Earth on Halloween of 1976, slightly dimmer than Pluto's AppMag of 14.5 that same year, when Charon was discovered.

Now, take into accout all the sky surveys and exploration that were operating throughout the 20th century. Between 1976 and 2020, what might be decently realistic discovery dates for Rogue Planet and its moons?

[Gurren Lagann]

The rogue planet itself would had likely been discovered in the 1970s or 1980s, with the discovery survey likely being the Catalina Sky Survey (limiting magnitude: +21.5). Its moons would had likely been found at around the time Hubble was first operational, so around the early-to-mid 1990s.

[PlutonianEmpire]

Nice. What might be some conceivable space missions to the planet? (Probes, orbiters, flybys, or even landers?)