Researchers believe there may be a planet that could sustain life, in the vicinity of a dying sun.
If confirmed, this would be the first time that a potentially life-supporting planet has been found orbiting such a star, called a "white dwarf".
The planet was detected in the star's "habitable zone", where it's neither too cold nor too hot to sustain life.
The study is published in the monthly notices of the Royal Astronomical Society.
Prof Jay Farihi of University College London, who led the study, said the observation was completely new to astronomers.
"This is the first time that anything has been seen in the habitable zone of a white dwarf. And thus there is a possibility of life on another world orbiting it," he told BBC News.
While very large stars become black holes when they die, smaller ones like our own Sun become white dwarves - stars that have used up all their nuclear fuel and lost their outer layers.
They are usually the size of a planet, and emit a bluish-white light when first formed.
The possible planet, which is 117 light years away from Earth, is thought to be 60 times closer to the star than our planet is to the Sun.