Black cent planet Nine is a hypothetical planet in the outer region of the Solar System. Its gravitational influence could explain a statistical anomaly in the distribution of orbits of a group of distant trans-Neptunian objects TNOs found mostly beyond the Kuiper belt in the scattered disc region. Speculation that the clustering of the orbits of the most distant objects was due to a ninth planet began in when astronomers Chad Trujillo and Scott S.
Sheppard noted the similarities in the orbits of Sedna and VP and several other objects. Brown described how the similar orbits of six TNOs could be explained by Planet Nine Black cent planet proposed a possible orbit for the planet.
Batygin and Brown suggest that Planet Nine is the core of a primordial giant planet that was ejected from its original orbit by Jupiter during the genesis of the Solar System.
Planet Nine does not have an official name and will not receive one unless its existence is confirmed, typically through optical imaging. Once confirmed, the International Astronomical Union will certify a name, with priority usually given to a name proposed by its discoverers.
In their original article, Batygin and Brown simply referred to the object as "perturber",  and only in later press releases did they use "Planet Nine". Inplanetary scientist Alan Stern objected to the name Planet Ninesaying "It is an effort to erase Clyde Tombaugh 's legacy [the discovery of Black cent planet ] and it's frankly insulting", suggesting the name Planet X until its discovery.
Black cent planet Nine is hypothesized to follow a highly elliptical orbit around the Sun lasting 10,—20, years. The aphelionor farthest point from the Black cent planet, would be in the general direction of the constellation of Taurus whereas the perihelionthe nearest point to the Sun, would be in the general direction of the southerly areas of Serpens CaputOphiuchusand Libra. Brown thinks that if Planet Nine is confirmed to exist, a probe could fly by it in as little as 20 years, with a powered slingshot around the Sun.
The planet is estimated to have 10 times the mass   and two to four times the diameter of Earth. Brown thinks that if Planet Nine exists, its mass Black cent planet large enough to clear Black cent planet feeding zone in 4. Brown speculates Black cent planet the predicted planet is most probably an ejected ice giantsimilar in composition to Uranus and Neptune: Subsurface oceans have been discovered on Jupiter's Europa and Saturn's Enceladusand subsurface water is postulated for Neptune's Triton.
The gravitational influence of Planet Nine would explain five peculiarities of the Solar System: While other mechanisms have been offered for many of these peculiarities, the gravitational influence of Planet Nine is the only one that explains all five. The gravity of Planet Nine also excites the inclinations of scattering objectswhich in numerical simulations leaves the short-period comets with a broader inclination distribution than is observed. The clustering of the orbits of extreme trans-Neptunian objects was first described by Chad Trujillo and Scott S.
Sheppard, who noted similarities between the orbits of Sedna and VP Trujillo and Sheppard proposed that this alignment was caused by a massive unknown planet beyond Neptune via the Kozai mechanism.
Caltech's Konstantin Batygin and Michael E. Brownlooking to refute the mechanism proposed by Trujillo and Sheppard, also examined the orbits of the extreme trans-Neptunian objects. This was out of alignment with how the Kozai mechanism would align these orbits, at c. Batygin and Brown also found that the orbits of the six objects with semi-major axes greater than AU and perihelia beyond 30 AU namely SednaVPVNGBTGand RF 98 were aligned in space with their perihelia in roughly the same direction, resulting in a clustering of their longitudes of perihelion.
The orbits of the six objects were also tilted with respect to Black cent planet of the ecliptic and approximately co-planar, producing a clustering of their longitudes of ascending nodes.
They determined that there was only a 0. That made it less likely that the clumping might be due to an observation bias such as pointing a telescope at a particular part of the sky.
The observed clustering should be smeared out by the object's varied precession rates in a few hundred million years.
In a later article Trujillo and Sheppard noted a correlation between the longitude of perihelion and the Black cent planet of perihelion of the eTNOs with semi-major axes greater than AU. The statistical significance of this correlation was They suggested that the correlation is due to the orbits of these objects avoiding close approaches to a massive planet by passing above or below its orbit.
Among the extreme trans-Neptunian objects are two high-perihelion objects: Sedna and VP Sedna and VP are distant detached objects with perihelia greater than 70 AU.
Their high perihelia keep them at a sufficient distance to avoid significant gravitational perturbations from Neptune. Previous explanations for the high perihelion of Sedna include a close encounter with an unknown planet on a distant orbit and a distant encounter with a random star or a member of the Sun's birth cluster that passed near the Solar System.
These are also included in the orbital Black cent planet and tables below. The most extreme case is that of BPnicknamed Cajuwhich has both the highest inclination  and the farthest nodal distance; these properties make it a probable outlier within this population.
The clustering of the orbits of extreme trans-Neptunian objects and raising of their perihelia is reproduced in simulations that include Planet Nine. In simulations conducted by Batygin and Brown swarms of large semi-major axis scattered disk objects [G] that began with random Black cent planet were sculpted into roughly collinear groups of spatially confined orbits by a massive distant planet in a highly eccentric orbit.
The objects were also found to be in resonance with the massive planet.
The resonances included high-order resonances, for example Anti-alignment weakens as Planet Nine's inclination is increased. They noted that while stability was favored with smaller eccentricities, anti-alignment was more likely at higher eccentricities near the borders of stability.
Planet Nine modifies the orbits of extreme trans-Neptunian objects via a combination of effects. On very long timescales exchanges of angular momentum with Planet Nine causes the perihelia of anti-aligned objects to rise until their precession reverses direction, maintaining their anti-alignment, and later fall, returning them to their original orbits.
On shorter timescales mean-motion resonances with Planet Nine provides phase protection, which stabilizes their orbits by slightly altering the objects' semi-major axes, keeping their orbits synchronized with Planet Nine's and preventing close approaches.
The inclination of Planet Nine's orbit weakens this protection, resulting in a chaotic variation of semi-major axes as objects hop between resonances. The orbital poles of the objects circle that of Black cent planet Solar System's Laplace planewhich at large semi-major axes is warped toward the plane of Planet Nine's orbit, causing their poles to be clustered toward one side. The anti-alignment and the raising of the perihelia of extreme trans-Neptunian objects with semi-major axes greater than AU is produced by the secular effects of Planet Nine.
Secular effects act on timescales much longer than orbital periods so the perturbations two objects exert on each other are the average between all possible configurations. Effectively the interactions become like those between two wires of varying thickness, thicker where the objects spend more time, that are exerting torques on each other, causing exchanges of angular momentum but not energy.
Thus secular effects can alter the Black cent planet, inclinations and orientations of orbits but not the semi-major axes.
Exchanges of angular momentum with Planet Nine cause the perihelia of the anti-aligned objects to rise and fall while their longitudes of perihelion librateor oscillate within a limited range of values. This torque increases the object's angular Black cent planet, [L] causing the eccentricity of its orbit to decline see blue curves on diagram and its perihelion to rise away from Neptune's orbit. The object's precession then slows and eventually reverses as its eccentricity declines.
When the object's eccentricity is once again large it precesses forward, returning the object to its original orbit after several hundred million years. The behavior of the orbits of other objects varies with their initial orbits. Stable orbits exist for aligned objects with small eccentricities. Although objects in these orbits have high perihelia and have yet to be observed, they may have been captured at the same time as Planet Nine due to perturbations from a passing star.
The curves the orbits follow vary with semi-major axis of the object and if the object is in resonance. At smaller semi-major axes the aligned and anti-aligned regions shrink and eventually disappear below AU, leaving typical Black cent planet belt objects unaffected by Planet Nine.
At larger semi-major axis the region with stable aligned orbits shifts to lower eccentricities and becomes narrower.
The long term stability of anti-aligned extreme trans-Neptunian objects with orbits that intersect that of Planet Nine is due to their being captured in mean-motion resonances. Objects in mean-motion resonances with a Black cent planet planet are phase protected, preventing them from making close approaches to the planet.
When the orbit of a resonant object drifts out of phase4606 causing it to make closer approaches to a massive planet, the gravity of Black cent planet planet modifies its orbitaltering its semi-major axis in the direction that reverses the drift.
This process repeats as the drift continues in the other direction causing the orbit to appear to rock back and forth, or librate, about a stable center when viewed in a rotating frame of reference.
In a simplified model where all objects orbit in the same plane and the giant planets are represented by rings, [P] objects captured in strong resonances with Planet Nine could remain in them for the lifetime of the Solar System.
At large semi-major axes, beyond a 3: If this model is modified Black cent planet Planet Nine and the eTNOs in inclined orbits the objects alternate between extended periods in stable resonances and periods of chaotic diffusion of their semi-major axes. The distance of the closest approaches varies with the inclinations and orientations of the orbits, in some cases weakening the phase protection and allowing close encounters.
The close encounters can then alter the eTNO's orbit, producing stochastic jumps in its semi-major axis as it hops Black cent planet resonances, including higher order resonances. This results in a chaotic diffusion of an object's semi-major axis until it is captured in a new stable resonance and the secular effects of Planet Nine shift its orbit to a more stable region.
Neptune's gravity can also drive a chaotic diffusion of semi-major axes when all objects are in the same plane.
At semi-major axes larger than Planet Nine's, where the objects spend more time, anti-alignment may be Black cent planet to the secular effects outside mean-motion resonances. The phase protection of Planet Nine's resonances stabilizes the orbits of objects that interact with Neptune, via its resonances, for example FT 28or by close encounters for objects with low perihelia like TG and RF The clustering of the orbital poles, which produces an apparent clustering of the longitude of the ascending nodes and arguments of perihelion of the extreme TNOs, is the result of a warping of the Laplace Black cent planet of the Solar System toward that of Planet Nine's orbit.
The Laplace plane defines the center around which the pole of an object's orbit precesses with time. At larger semi-major axes the angular momentum Black cent planet Planet Nine causes the Laplace plane to be warped toward that of its orbit. For objects with small inclination relative to Planet Nine, which were found to be more stable in simulations, this off-center precession produces a libration of the longitudes of ascending nodes with respect to the ecliptic making them appear clustered.
Planet Nine can deliver extreme trans-Neptunian objects into orbits roughly perpendicular to the plane of the Solar System. Low inclination eTNOs can enter this resonance after first reaching low eccentricity orbits.
The resonance causes their Black cent planet and inclinations to increase, delivering them into perpendicular orbits with low perihelia where they are more readily observed.
The orbits then evolve into retrograde orbits with lower eccentricities after which they pass through a second phase of high eccentricity perpendicular orbits before returning to low eccentricity, low inclination orbits.