Astronomers Mike Brown and Konstantin Batygin of the California Institute of Technology in Pasadena have reported the discovery of a Neptune-sized object outside Pluto's orbit, which is 10 times heavier than Earth. The authors published the results of the search for Planet X in The Astronomical Journal, and Science News briefly tells about them.
The planet revolves around the Sun in an elongated orbit (and in a plane inclined relative to the Earth's orbit) with a period of 15 thousand years. Its chemical composition is similar to that of the gas giants Uranus and Neptune. As Brown and Batygin believe, the object 4.5 billion years ago was knocked out of the protoplanetary disk near the Sun.
The closest distance between the Sun and the detected object is 200 astronomical units (this is seven times the distance between Neptune and the star). The maximum distance of Planet X is estimated at 600-1200 astronomical units, which puts its orbit outside the Kuiper belt, in which Pluto is located.
Image: NASA / JPL-CALTECH
Scientists discovered the new planet by analyzing the data on the gravitational perturbation it exerts on other celestial bodies. As noted by Brown and Batygin, astronomers will believe in their discovery when they can observe the planet through a telescope. To do this, they reserved time at the Japanese Subaru Observatory in Hawaii.
Confirmation of the existence of a celestial body will take five years. If discovered, the object could become the ninth planet in the solar system. Brown and Batygin estimate the probability of error at 0.007 percent. Earlier searches for Planet X in the solar system led scientists to discover Neptune (in 1864) and Pluto (in 1930).