MADRID – A scientific team has released data about the star closest to our sun that strongly suggests the possibility of undiscovered planets after detecting a massive dust belt encircling it, the latest issue of the Astrophysical Journal Letters said on Friday.
Although invisible to the naked eye, Proxima Centauri is a red dwarf star only 4.25 light years away.
What was already known is that orbiting around it is an Earth-like exoplanet, Proxima Centauri b, discovered in 2016 and located in a “temperate orbit,” meaning if our Earth was at that same location, the oceans would neither freeze nor boil.
The newly detected dust-belt is roughly between one and three Astronomical Units distant from the Proxima Centauri and has a temperature of around minus 230 degrees Celsius similar to our own Kuiper belt, located some four light-hours – 30 Astronomical Units – away from our Sun.
An astronomical unit (AU) is the average distance between Earth and the Sun.
According to notes published by the European Space Observatory and Spain’s High Council for Scientific Research, this dust belt discovery is of extreme importance as it signals the presence of a more complex exoplanetary system, that is, more than one planet orbiting the star.
According to Guillem Anglada, of the Andalucian Astrophysics Institute and a leading author of the article, “The PC dust belt is located roughly between one and three AU’s away, we cannot be more precise but we have been able to calculate its approximate whereabouts,” he told EFE.
The discovery has been possible thanks to the ESO’s ALMA observatory in Chile, which also points to the possibility of another dust cloud, further away, some 30 AUs from Proxima Centauri, also mimicking the Solar System’s Oort Cloud, a sphere of cosmic debris enveloping our Solar System, some 50 AUs distant from our Sun.
Until now astrophysicists questioned the possibility that “a star smaller than our Sun would be unable to retain a dust belt so far away,” Anglada added.
Another reason Proxima Centauri’s star system is of such interest is that there are plans to explore it by sending very small nano-spaceships equipped with solar sails propelled by lasers.
This initiative, known as the Starshot project, is backed, among others, by Facebook’s Mark Zuckerberg and theoretical physicist and cosmologist, Stephen Hawking.
Another reason is that Proxima Centauri may reveal many details of how our own Solar system and Earth were created some 4.6 billion years ago.