A mysterious ring of cosmic dust has been discovered around Proxima Centauri, the closest star to our own sun.
Scientists already know one rocky exoplanet - known as Proxima B - is orbiting the star, but now it appears there could be more.
The ALMA Observatory in Chile made the discovery, and estimations put the ring of dust at between one and four times the distance from Proxima Centauri as the Earth is from the sun.
At four light years distance, the red dwarf Proxima Centauri is the closest star to our own. It is orbited by the Earth-sized temperate world Proxima b, discovered in 2016 and the closest planet to the Solar System.
The observations also hint at the presence of an even cooler outer dust belt and may indicate the presence of an elaborate planetary system.
These structures are similar to the much larger belts in the solar system and are also expected to be made from particles of rock and ice that failed to form planets
Lead author scientific investigator Guillem Anglada from the Instituto de Astrof sica de Andaluc a (CSIC), Granada, Spain, explained the significance of this find.
He said: "The dust around Proxima is important because, following the discovery of the terrestrial planet Proxima b, it's the first indication of the presence of an elaborate planetary system, and not just a single planet, around the star closest to our Sun."
He added dust belts are the remains of material that did not form into larger bodies such as planets.
The particles of rock and ice in these belts vary in size from the tiniest dust grain, smaller than a millimetre across, up to asteroid-like bodies many kilometres in diameter.
Dust appears to lie in a belt that extends a few hundred million kilometres from Proxima Centauri and has a total mass of about one hundredth of the Earth's mass.
This belt is estimated to have a temperature of about -230 degrees Celsius, as cold as that of the Kuiper Belt in the outer Solar System.
There could also be an outer belt of even colder dust about ten times further out.
If confirmed, the nature of an outer belt is intriguing, given its very cold environment far from a star that is cooler and fainter than the Sun.
Both belts are much further from Proxima Centauri than the planet Proxima b, which orbits at just four million kilometres from its parent star.
Mr Anglada added: "This result suggests that Proxima Centauri may have a multiple planet system with a rich history of interactions that resulted in the formation of a dust belt.
"Further study may also provide information that might point to the locations of as yet unidentified additional planets."
Co author Reader in Astronomy Dr Guillem-Anglada-Escud of Queen Mary University of London lead the discovery of Proxima b and is not related to Mr Anglada.
He added: "The cold dust detected by ALMA is really important because it shows the new level of detail that we can reach in understanding planetary systems when focusing on these very nearby stars with new generation observatories.
"These observations show that Proxima Centauri seems to hold a rich planetary system with an interesting dynamical history rather than just Proxima b, which we discovered last year."
Proxima Centauri's planetary system is also particularly interesting because there are plans, the Starshot project, for future direct exploration of the system with microprobes attached to laser-driven sails.
A knowledge of the dust environment around the star is essential for planning such a mission.
Co-author Pedro Amado, also from CSIC said: "These first results show that ALMA can detect dust structures orbiting around Proxima.
"Further observations will give us a more detailed picture of Proxima's planetary system.
"In combination with the study of protoplanetary discs around young stars, many of the details of the processes that led to the formation of the Earth and the Solar System about 4600 million years ago will be unveiled.
"What we are seeing now is just the appetiser compared to what is coming!"
The study was published in Astrophysical Journal Letters.