Something like that could have easily, influenced the trajectory of oumuamu and 2i Korisov if the gravity well extended far enough. The reason I mentioned oumuamua, 2i Korisov, and mega comet, now is if this thing was in between the Oort cloud in the Kuiper belt that would explain a great deal. It's seems to me it"s too much of a coincidence that in the course of four years we have three unprecedented visitors and if there is a planet 9 in between the Oort cloud and the Kuiper belt that would explain a great deal. Let's just hope that if there's any more Interlopers it's not going 2 be the beginning of another late heavy bombardment.The volume of space for the Oort Cloud is unimaginable ~ 1.4E40 cu. km.! [Using a 400AU to 100k AU radii. The 400AU, less than normal for the inner Oort, was to take in the P9 orbital distance.]
A planet 6x the size of Earth out there is smaller in comparison to a single drop of water somewhere in the Pacific Ocean (710million cu. km.).
It's movement and gravity extends much farther, but keep that vol. comparison in mind. Also Planet 9, as proposed is around 600AU in distance, so it doesn't even reach what many consider to be the inner region of the O.C.
When we ask "Is there a 9th planet" it's important to remain focussed on the concept of the question. Technically Pluto is still a "planet" but no longer considered a "full planet", instead defined as a "minor planet". Unfortunately there are far too many of these for the term to mean very much at all, although there is of course a subgroup of minor planets called "dwarf planets" that could be considered worth giving a decent amount of credence to.Please give distinctive details of your vision of planet 9 and try to name it.
I messaged the (hunt for 9th) team and said load up all the star pictures from the last forever run them on a computer and look for stars that vanish for any length of time.Yes, at 600AU and 3x the radius of Earth, it would have a visual magnitude of only about 22.
The IR band has a better chance.
Could have some decent size planets way out in the boonies that still haven't cleared the orbital path since 400+ AU orbits take a very long time.We can determine if a planet qualifies as such since planet-clearing can be modeled within astrophysics.
Here is a paper that establishes whether or not a given mass with a given orbit can clear its orbit over a long period of time. [There is a thread on this with a graph somewhere on this site.]
Trojans coming along for the ride (L4 & L5) are not part of the clearing determination, otherwise Jupiter isn't a planet.
P9 may be evading astronomers if its background is the galactic plane where the glow causes too much noise.
I'm unclear of what you're asking regarding the orbit of satellites.Helio, IAU let themselves in for a lot of trouble (2006) with the 'clearing orbit' clause. Why should not that apply to satellites?
Yep this is true for exoplanets. We are incapable yet of discovering exo-dwarf planets, or smaller. [There may be one or two tight-orbiting small objects, admittedly, now known.]Definition:
A planet is any spherical (near-spherical) body which orbits a star and which gets called a planet until someone says that it isn't.
I think it means that no other body will survive being in that same orbit because the mass of the "planet" is great enough to eject all lesser bodies.Helio, is there anything in IAU 2006 which defines what clearing an orbit means?
I assume that it's a moon when its orbit is defined by the mass of the host body it is orbiting. But, some flexibility seems to be exercised in the case of Pluto and Charon. When the barycenter is outside the surface of both bodies, what then? I doubt few call Pluto a binary dwarf planet. The only exception would be when the science involves barycenters, etc. Like anyone, scientists don't seem to want to be so pedantic that they elect to stress the use of labels. Labels are only useful to an extent they add clarity in eschewing obfuscation.Specifically, when is a moon not a moon?
Very nice. Here are my free tweaks:
Ah, I almost asked if it was your definition or another's. It looked like your work.