Ohio State University | 2014 Oct 15
First “ice giant” planet found in another solar system
Our view of other solar systems just got a little more familiar, with the discovery of a planet 25,000 light-years away that resembles our own Uranus.
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 is the first time anyone has spotted a twin for our so-called “ice giant” planets, Uranus and Neptune.
An international research team led by Radek Poleski, postdoctoral researcher at The Ohio State University, described the discovery in a paper appearing online in The Astrophysical Journal.
While Uranus and Neptune are mostly composed of hydrogen and helium, they both contain significant amounts of methane ice, which gives them their bluish appearance. Given that the newly discovered planet is so far away, astronomers can’t actually tell anything about its composition. But its distance from its star suggests that it’s an ice giant—and since the planet’s orbit resembles that of Uranus, the astronomers are considering it to be a Uranus analog.
Regardless, 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 find may help solve a mystery about the origins of the ice giants in our solar system ...
Triple Microlens OGLE-2008-BLG-092L: Binary Stellar System with a Circumprimary Uranus-type Planet - Radosław Poleski et al
- Astrophysical Journal 795(1) 42 (2014 Nov 01) DOI: 10.1088/0004-637X/795/1/42
arXiv.org > astro-ph > arXiv:1408.6223 > 26 Aug 2014 (v1), 05 Sep 2014 (v2)