Planet Xs...

RX J1131-1231 is about 6 billion light-years away. It is a lensed quasar; gravitational lensing caused by an intervening elliptical galaxy (center, yellow) has magnified and multiplied the image of RX J1131 into four images (pink) as seen with the Chandra X-ray Observatory.
X-ray: NASA/CXC/Univ of Michigan/R.C.Reis et al; Optical: NASA/STScI

Topics: Astronomy, Astrophysics, Exoplanets

Discoveries of exoplanets in our galaxy exceed 3,700 to date, but if that’s not enough for you, astronomers are now probing outside of the Milky Way to find exoplanets in other galaxies. A group of researchers at the University of Oklahoma has just announced the discovery of a large population of free-floating planets in a galaxy 3.8 billion light-years away. Their results were published February 2 in the Astrophysical Journal Letters.

The researchers used a method known as quasar microlensing, which has traditionally been used to study the disk-like regions around supermassive black holes where material gathers as it spirals in toward the event horizon. When a distant quasar is eclipsed by a closer galaxy, the intervening galaxy will create several magnified replica images of the quasar. These replicas are further magnified by stars in the interloping galaxy to create a final super-magnified image that can be used to study the quasar in detail.

Astronomers report a possible slew of extragalactic exoplanets
Mara Johnson-Groh, Astronomy Magazine