Astronomers have found a gap in a disc of dust at the red dwarf star TW Hydrae.
The gap is located at about twice the distance of Neptune from the Sun.

The gap is only a strong indication of a planet, though it is far from confirmed since it have not been directly observed yet.
Yet if confirmed it might be a challenge on existing theories on how planets form. Since a planet at such a distance would take a very long time to accumulate material in its orbit around the star.

Source: Space Telescope Science Institute