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700 AU is way past heliopause, firmly in the interstellar space. Same, 15 times farther than Pluto is definitely away from the Solar system "proper". It's about

by nine_k 2y ago

700 AU is way past heliopause, firmly in the interstellar space. Same, 15 times farther than Pluto is definitely away from the Solar system "proper". It's about 100 light-hours away from Sun. I wonder how could this object be counted as a "planet" belonging to the Solar system, even if it were the size of Jupiter. But it's an object "estimated to be 2 to 4 times the radius, and about ten times the mass of the Earth". This must be another class of celestial bodies, some jumbo-sized Oort cloud object.

manquer 2y ago
As long it is orbiting the sun, i.e bound by the solar gravitational field then it is in the solar system? Also depending how elliptical the orbit, is the perigee might be much closer than 700AU, while still being further than Pluto's orbit. For all we know 700 AU is the apogee and say the perigee is 70 AU (1.4x Pluto's apogee ).
- chgs 2y ago
  Perigee is lowest point in an orbit around Earth. Perihhelion for sun orbits. Periapsis for the general term.
- goku12 2y ago
  > As long it is orbiting the sun The body must also be large enough to clear other bodies in the same orbit, except at the Trojan positions (L4 and L5), to be considered as a planet. Otherwise it would just be a Trans-Neptunian Object (TNO) or a Kuiper Belt Object (KBO) at these distances. It obviously does in this case. But this pedantic detail is rather important. It was used to demote Pluto a few years back.
  - viraptor 2y ago
    > It obviously does in this case. Does it? Would we actually know if there was another slightly more sparse belt at 700AU? If we can't track a large planet in that area, why would we be certain about the belt? Alternatively, if it's an external object captured by the Sun, how would we even classify it as clearing or not if there's nothing to clear?
    - goku12 2y ago
      Well, apparently the object causes bunching of other bodies in the Kuiper belt. And it would have got enough time to complete a few orbits. I assume that at some point, the other objects on its orbit would have been thrown off course or consumed by the planet. > how would we even classify it as clearing or not if there's nothing to clear? I assume that it's based on mathematical modeling.

by nine_k 2y ago

manquer 2y ago

As long it is orbiting the sun, i.e bound by the solar gravitational field then it is in the solar system? Also depending how elliptical the orbit, is the perigee might be much closer than 700AU, while still being further than Pluto's orbit. For all we know 700 AU is the apogee and say the perigee is 70 AU (1.4x Pluto's apogee ).

chgs 2y ago
Perigee is lowest point in an orbit around Earth. Perihhelion for sun orbits. Periapsis for the general term.
goku12 2y ago
> As long it is orbiting the sun The body must also be large enough to clear other bodies in the same orbit, except at the Trojan positions (L4 and L5), to be considered as a planet. Otherwise it would just be a Trans-Neptunian Object (TNO) or a Kuiper Belt Object (KBO) at these distances. It obviously does in this case. But this pedantic detail is rather important. It was used to demote Pluto a few years back.
- viraptor 2y ago
  > It obviously does in this case. Does it? Would we actually know if there was another slightly more sparse belt at 700AU? If we can't track a large planet in that area, why would we be certain about the belt? Alternatively, if it's an external object captured by the Sun, how would we even classify it as clearing or not if there's nothing to clear?
  - goku12 2y ago
    Well, apparently the object causes bunching of other bodies in the Kuiper belt. And it would have got enough time to complete a few orbits. I assume that at some point, the other objects on its orbit would have been thrown off course or consumed by the planet. > how would we even classify it as clearing or not if there's nothing to clear? I assume that it's based on mathematical modeling.