First 'Uranus-like' planet discovered in another solar system

Astronomers recently found an "ice giant" planet in another solar system 25,000 light-years away that resembles like Earth's Uranus for the first time ever.

Astronomers have discovered hundreds of planets around the Milky Way, including rocky planets similar to Earth and gas planets similar to Jupiter. But there is a third type of planet in our solar system; part gas, part ice and this was the first time anyone has spotted a twin for our so-called "ice giant" planets, Uranus and Neptune.

The newly discovered planet leads a turbulent existence; it orbits one star in a binary star system, with the other star close enough to disturb the planet's orbit.

The binary star system lies in the Milky Way galaxy, in the direction of Sagittarius. The first star would be about two thirds as massive as Earth's sun, and the second star would be about one sixth as massive. The planet was four times as massive as Uranus, but it orbits the first star at almost exactly the same distance as Uranus orbits our sun.

The astronomers spotted the solar system due to a phenomenon called gravitational microlensing; when the gravity of a star focuses the light from a more distant star and magnifies it like a lens. Very rarely, the signature of a planet orbiting the lens star appears within that magnified light signal.

The research is published in The Astrophysical Journal.