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White Dwarf (Illustration)
Photo: Mark A. Garlick / The Royal Astronomical Society
A planet 117 light-years from Earth likely has conditions in which life could exist.
In the discovered "habitable zone" it is neither too hot nor too cold for water, writes the British Royal Astronomical Society in a statement.
The planet orbits a so-called white dwarf - a rather small, old star.
The observation is completely new for the researchers, study leader Jay Farihi from University College London told the BBC: "It was a shock for the team".
If the assumption is confirmed, it will be the first time that a potentially habitable planet has been discovered orbiting a white dwarf.
"When we find one planet, it usually means there are many more," says Farihi.
The fact that the planet is where the researchers suspect it to be can be deduced from the movement of 65 moon-sized structures orbiting the white dwarf.
Their distances from each other did not change - apparently because the gravity of the planet affects them.
So it must be in the vicinity.
In the next step, the scientists want to look for direct evidence of its existence.
Our sun will also eventually end up as a white dwarf.
In a few billion years, it first transforms into a so-called red giant, expands and absorbs the neighboring planets Mercury and Venus.
In the end, a cooling white dwarf remains in a planetary nebula.
Most stars transform into such, about the size of the earth, crystal balls.
Whether there could be the right conditions for liquid water and thus life on a planet orbiting a white dwarf depends on the distance.
Too close would be too hot, too far away too cold.
In the area identified by the astronomers, the conditions are "just right."
The discovered planet orbits its star at a distance that is 60 times smaller than the distance between the earth and the sun.
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