Planet X — The current status

  title={Planet X — The current status},
  author={P. Seidelmann and Robert S. Harrington},
  journal={Celestial mechanics},
Neptune and Pluto were discovered because of predictions derived from the differences between the observations and ephemerides of Uranus, but Pluto wasn't the predicted planet and the discrepancies still exist. This continuing existence of systematic differences between the observations and ephemerides of Uranus and Neptune has led to predictions of a Planet X. The demise of the dinosaurs and the existence of comets have been cited as additional evidence for another celestial object.Therefore… 
Constraints on the location of a putative distant massive body in the Solar System from recent planetary data
We analytically work out the long-term variations caused on the motion of a planet orbiting a star by a very distant, pointlike massive object X. Apart from the semi-major axis a, all the other
Dark Matter in the Solar System
There is little direct dynamical evidence for dark matter in the solar system. However, fairly general models for the formation of the planetary system predict that dark matter in the form of fossil
Gravitational Anomalies in the Solar System
Mindful of the anomalous perihelion precession of Mercury discovered by Le Verrier in the second half of the nineteenth century and its successful explanation by Einstein with his General Theory of
On the unmodeled perturbations in the motion of uranus
In this paper we apply a numerical method to determine unmodeled perturbations in an attempt to explain the observed discrepancies in the motion of Uranus. We find that the estimated perturbation
Rapid dynamical evolution of giant comet Chiron
Numerical simulation of orbits like that of the giant comet Chiron show a distinct asymmetry between past and future. Simulations extending ±100,000 years from the present suggest that on this
Inverse Problem of Astrodynamics
We consider the problem of determining the center of mass of an unknown gravitational body, using the disturbances in the motion of observed celestial bodies. In this paper an universal approach to
The Exoplanet Handbook
1. Introduction 2. Radial velocities 3. Astrometry 4. Timing 5. Microlensing 6. Transits 7. Imaging 8. Host stars 9. Brown dwarfs and free-floating planets 10. Formation and evolution 11. Interiors


Periodic comet showers and planet X
The discovery1 that Pluto's mass is insufficient to explain the discrepancies in the motions of the outer planets has led to the prediction of a tenth planet (planet X) of mass ∼1–5 M⊕ beyond the
Dynamical constraints on the mass and perihelion distance of Nemesis and the stability of its orbit
It has been suggested1,2 that the observed periodic extinction of species at intervals of 26 Myr (ref. 3) may be catalysed by a hypothetical stellar companion of the Sun, Nemesis, with an orbital
The Location of Planet X
Observed positions of Uranus and Neptune along with residuals in right ascension and declination are used to constrain the location of a postulated tenth planet. The residuals are converted into
Galileo's observations of Neptune
The planet Neptune was discovered in 1846. As its period of revolution is almost 165 years, Neptune has not yet completed one revolution since its discovery. Largely as a result of this, its orbit is
Systematic differences between planetary observations and ephemerides.
For the 1984 edition of the Astronomical Almanac and a number of other national ephemerides, a new set of ephemerides was introduced. These ephemerides were prepared cooperatively by the Jet
How stable is an astronomical clock that can trigger mass extinctions on Earth?
  • P. Hut
  • Physics, Geology
  • 1984
The periodicity in mass extinctions observed in the fossil record1,2 may be driven by an astronomical clock consisting of a companion star to the Sun3,4. Each perihelion passage of the companion star
The passage of a 'Nemesis'-like object through the planetary system
The probability that passing stars could have perturbed the hypothetical stellar companion, Nemesis, into an orbit that penetrates the planetary system is about 15%. The planetary orbits crossed by
Dynamical evidence for Planet X
The dynamical evidence for a planet beyond the orbit of Neptune is reviewed. Three years of radio tracking data from Pioneer 10 can be fit to the noise level with no evidence for unmodelled